iio: hx711: add data-ready-delay

This patch adds an additional property in the device tree for adjusting the delay between a rising edge on PD_SCK until data is ready on DOUT.

This is necessary because of parasitic capacitance on different systems.

In the last patch there is a fix of dtc warning if someone is using the given example.

Changes against v4:
- Thanks to Rob for giving me explanations
- make square wave with clock PD_SCK and change documentation for it

Changes against v3:
- added suggestion of Rob to rename the new attribute to clock-frequency

Changes against v2:
- added suggestion of Jonathan to add vendor prefix in device tree setting

Andreas Klinger (3):
iio: hx711: add clock-frequency property in DT
iio: hx711: add delay until DOUT is ready
iio: hx711: fix spurious unit-address in example

 .../devicetree/bindings/iio/adc/avia-hx711.txt     |  8 ++++-
 drivers/iio/adc/hx711.c                            | 39 ++++++++++++++++++++++
 2 files changed, 46 insertions(+), 1 deletion(-)

2.1.4