arm64: dts: qcom: add sdm670 and pixel 3a device trees

The Qualcomm Snapdragon 670 has been out for a while. Add a device tree
for it and the Google Pixel 3a as the first device.

The Pixel 3a has the same bootloader issue as the Pixel 3 and will not work
on Android 10 bootloaders or later until it gets fixed for the Pixel 3.

SoC Initial Features:
 - power management
 - clocks
 - pinctrl
 - eMMC
 - USB 2.0
 - GENI I2C
 - IOMMU
 - RPMh
 - interrupts

Device-Specific Initial Features:
 - side buttons (keys)
 - regulators
 - touchscreen

Signed-off-by: Richard Acayan <mailingradian@gmail.com>

arch/arm64/boot/dts/qcom/Makefile

@@ -122,6 +122,7 @@ dtb-$(CONFIG_ARCH_QCOM)	+= sdm630-sony-xperia-nile-voyager.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm632-fairphone-fp3.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm636-sony-xperia-ganges-mermaid.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm660-xiaomi-lavender.dtb
+dtb-$(CONFIG_ARCH_QCOM)	+= sdm670-google-sargo.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm845-cheza-r1.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm845-cheza-r2.dtb
 dtb-$(CONFIG_ARCH_QCOM)	+= sdm845-cheza-r3.dtb