dt-bindings: net: wireless: qca,ath9k: convert to the json-schema

This replaces the existing .txt binding file. Furthermore, this also helps with validating DTS files.

Introduced binding changes:
1. added inherited mac-address nvmem property
2. added inherited ieee80211-freq-limit property
3. added new calibration nvmem property
4. added second example (taken from the Netgear WNDR3700v2)
Reason: Setting qca,no-eeprom; takes presedence over nvmem-cells. I think a different example is needed, because the driver can only reads from one calibration source per device.
5. (re-added) chip list (based on data from ath9k's pci.c)

Added binding .yaml to MAINTAINERS.

---
v1 -> v2:
- added second example (pci device - AR9220)
- added commented chip list from the qca,ath9k.txt+ath9k's pci.c

v2 -> v3:
- forgot to include patch version in tag. Oops. (Please ignore the v2 with the missing v2 I just sent.)

(I hope my changes didn't invalidate Rob's review there. I did run "make dt_binding_check" and no warning/error came up.)

---
 .../bindings/net/wireless/qca,ath9k.txt       | 48 ----------
 .../bindings/net/wireless/qca,ath9k.yaml      | 90 +++++++++++++++++++
 MAINTAINERS                                   |  1 +
 3 files changed, 91 insertions(+), 48 deletions(-)
 delete mode 100644 Documentation/devicetree/bindings/net/wireless/qca,ath9k.txt
 create mode 100644 Documentation/devicetree/bindings/net/wireless/qca,ath9k.yaml

deleted file mode 100644
index aaaeeb5f935b..000000000000
@@ -1,48 +0,0 @@
-* Qualcomm Atheros ath9k wireless devices
-
-This node provides properties for configuring the ath9k wireless device. The
-node is expected to be specified as a child node of the PCI controller to
-which the wireless chip is connected.
-
-Required properties:
-- compatible: For PCI and PCIe devices this should be an identifier following
-		the format as defined in "PCI Bus Binding to Open Firmware"
-		Revision 2.1. One of the possible formats is "pciVVVV,DDDD"
-		where VVVV is the PCI vendor ID and DDDD is PCI device ID.
-		Typically QCA's PCI vendor ID 168c is used while the PCI device
-		ID depends on the chipset - see the following (possibly
-		incomplete) list:
-			- 0023 for AR5416
-			- 0024 for AR5418
-			- 0027 for AR9160
-			- 0029 for AR9220 and AR9223
-			- 002a for AR9280 and AR9283
-			- 002b for AR9285
-			- 002c for AR2427
-			- 002d for AR9227
-			- 002e for AR9287
-			- 0030 for AR9380, AR9381 and AR9382
-			- 0032 for AR9485
-			- 0033 for AR9580 and AR9590
-			- 0034 for AR9462
-			- 0036 for AR9565
-			- 0037 for AR9485
-- reg: Address and length of the register set for the device.
-
-Optional properties:
-- qca,no-eeprom: Indicates that there is no physical EEPROM connected to the
-			ath9k wireless chip (in this case the calibration /
-			EEPROM data will be loaded from userspace using the
-			kernel firmware loader).
-
-The MAC address will be determined using the optional properties defined in
-net/ethernet.txt.
-
-In this example, the node is defined as child node of the PCI controller:
-&pci0 {
-	wifi@168c,002d {
-		compatible = "pci168c,002d";
-		reg = <0x7000 0 0 0 0x1000>;
-		qca,no-eeprom;
-	};
-};

index 1a8e641d7edf..5a3af6b25000 100644
@@ -15457,6 +15457,7 @@ M:	[email protected]
 L:	[email protected]
 S:	Supported
 W:	https://wireless.wiki.kernel.org/en/users/Drivers/ath9k
+F:	Documentation/devicetree/bindings/net/wireless/qca,ath9k.yaml
 F:	drivers/net/wireless/ath/ath9k/
 
 QUALCOMM CAMERA SUBSYSTEM DRIVER

2.33.0

My bot found errors running 'make DT_CHECKER_FLAGS=-m dt_binding_check' on your patch (DT_CHECKER_FLAGS is new in v5.13):

yamllint warnings/errors:
./Documentation/devicetree/bindings/net/wireless/qca,ath9k.yaml:23:21: [error] syntax error: found character '\t' that cannot start any token (syntax)

dtschema/dtc warnings/errors:

doc reference errors (make refcheckdocs):

See https://patchwork.ozlabs.org/patch/1531944

This check can fail if there are any dependencies. The base for a patch series is generally the most recent rc1.

If you already ran 'make dt_binding_check' and didn't see the above error(s), then make sure 'yamllint' is installed and dt-schema is up to date:

pip3 install dtschema --upgrade

Please check and re-submit.