sunxi: board: Add PinePhone DT selection logic

There are two different publicly-released revisions of the PinePhone
hardware, versions 1.1 and 1.2; and they need different device trees.
Since some GPIO pins were rerouted, we can use that to distinguish
between them.

Acked-by: Maxime Ripard <mripard@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
diff --git a/arch/arm/mach-sunxi/Kconfig b/arch/arm/mach-sunxi/Kconfig
index be0822b..8421f3b 100644
--- a/arch/arm/mach-sunxi/Kconfig
+++ b/arch/arm/mach-sunxi/Kconfig
@@ -1010,4 +1010,11 @@
 	  option, the device tree selection code specific to Pine64 which
 	  utilizes the DRAM size will be enabled.
 
+config PINEPHONE_DT_SELECTION
+	bool "Enable PinePhone device tree selection code"
+	depends on MACH_SUN50I
+	help
+	  Enable this option to automatically select the device tree for the
+	  correct PinePhone hardware revision during boot.
+
 endif