sunxi: Kconfig: introduce CONFIG_SUNXI_HIGH_SRAM

Traditionally Allwinner SoCs have their boot ROM mapped just below 4GB,
while the first SRAM region is mapped at address 0.
With the extended physical memory support of the A80 this was changed,
so the BROM is now at address 0 and the SRAM region starts right behind
this at 64KB. This configuration seems to be called "high SRAM".
Instead of enumerating the SoCs which have copied this configuration,
let's call a spade a spade and introduce a Kconfig option for this setup.
SoCs implementing this (A80, A64 and H5, so far), can then select this
configuration.
Simplify the config header definition on the way.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Jagan Teki <jagan@openedev.com>
diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index ea0d658..654ec73 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -27,6 +27,17 @@
 config SPL_SERIAL_SUPPORT
 	default y
 
+config SUNXI_HIGH_SRAM
+	bool
+	default n
+	---help---
+	Older Allwinner SoCs have their mask boot ROM mapped just below 4GB,
+	with the first SRAM region being located at address 0.
+	Some newer SoCs map the boot ROM at address 0 instead and move the
+	SRAM to 64KB, just behind the mask ROM.
+	Chips using the latter setup are supposed to select this option to
+	adjust the addresses accordingly.
+
 # Note only one of these may be selected at a time! But hidden choices are
 # not supported by Kconfig
 config SUNXI_GEN_SUN4I
@@ -120,6 +131,7 @@
 config MACH_SUN9I
 	bool "sun9i (Allwinner A80)"
 	select CPU_V7
+	select SUNXI_HIGH_SRAM
 	select SUNXI_GEN_SUN6I
 	select SUPPORT_SPL
 
@@ -127,6 +139,7 @@
 	bool "sun50i (Allwinner A64)"
 	select ARM64
 	select SUNXI_GEN_SUN6I
+	select SUNXI_HIGH_SRAM
 	select SUPPORT_SPL
 
 endchoice