ARM: sunxi: Add basic A23 support

The basic blocks of the A23 are similar to the A31 (sun6i). Re-use
sun6i code for initial clock, gpio, and uart setup.

There is no SPL support for A23, as we do not have any documentation
or sample code for DRAM initialization.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Ian Campbell <ijc@hellion.org.uk>
diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 9892a34..449c046 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -1,4 +1,4 @@
-if TARGET_SUN4I || TARGET_SUN5I || TARGET_SUN6I || TARGET_SUN7I
+if TARGET_SUN4I || TARGET_SUN5I || TARGET_SUN6I || TARGET_SUN7I || TARGET_SUN8I
 
 config SYS_CONFIG_NAME
 	string
@@ -6,6 +6,7 @@
 	default "sun5i" if TARGET_SUN5I
 	default "sun6i" if TARGET_SUN6I
 	default "sun7i" if TARGET_SUN7I
+	default "sun8i" if TARGET_SUN8I
 
 config SYS_CPU
 	default "armv7"