sunxi: Add OrangePi PC 2 initial support

The OrangePi PC 2 is a typical SBC with the 64-bit Allwinner H5 SoC.
Add a (64-bit only) defconfig defining the required options to build
the U-Boot proper.

Create a new .dts file for it by including the (32-bit) H3 SoC .dtsi
and changing the differing components accordingly.
This is a preliminary device tree mostly for U-Boot's own sake, it
is expected to be updated once the official DT gets accepted upstream.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
[squash the commits, update the commit message]
Signed-off-by: Jagan Teki <jagan@openedev.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 462c690..0286fb3 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -299,6 +299,8 @@
 	sun8i-h3-orangepi-plus.dtb \
 	sun8i-h3-orangepi-plus2e.dtb \
 	sun8i-h3-nanopi-neo.dtb
+dtb-$(CONFIG_MACH_SUN50I_H5) += \
+	sun50i-h5-orangepi-pc2.dtb
 dtb-$(CONFIG_MACH_SUN50I) += \
 	sun50i-a64-pine64-plus.dtb \
 	sun50i-a64-pine64.dtb