poky-tiny: Update kernel to 3.19

Additionally, allow PREFERRED_VERSION for linux-yocto-tiny to be overridden

This addresses the warnings from the kernel configcheck:

WARNING: [kernel config]: specified values did not make it into the kernel's final configuration:

Value requested for CONFIG_ATA_PIIX not in final ".config" Requested value: "CONFIG_ATA_PIIX=y"
Actual value set: ""

Value requested for CONFIG_BRCMFMAC_SDIO not in final ".config" Requested value: "CONFIG_BRCMFMAC_SDIO=y"
Actual value set: ""

Value requested for CONFIG_NR_CPUS not in final ".config" Requested value: "CONFIG_NR_CPUS=64"
Actual value set: "CONFIG_NR_CPUS=8"

Value requested for CONFIG_PM not in final ".config" Requested value: "CONFIG_PM=y"
Actual value set: ""

[YOCTO #7478]

---
 meta-yocto/conf/distro/poky-tiny.conf | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

index aa60e77..f4a772e 100644
@@ -37,7 +37,7 @@ DISTRO = "poky-tiny"
 # Distro config is evaluated after the machine config, so we have to explicitly
 # set the kernel provider to override a machine config.
 PREFERRED_PROVIDER_virtual/kernel = "linux-yocto-tiny"
-PREFERRED_VERSION_linux-yocto-tiny = "3.14%"
+PREFERRED_VERSION_linux-yocto-tiny ?= "3.19%"
 
 # We can use packagegroup-core-boot, but in the future we may need a new packagegroup-core-tiny
 #POKY_DEFAULT_EXTRA_RDEPENDS += "packagegroup-core-boot"

2.1.0