sunxi: add Linksprite pcDuino v1/v2 support

Add support for a sun4i board built by Linksprite. This addition covers
both v1 and v2 versions. As the board has been working with 408MHz memory
setting in the u-boot-sunxi branch, and has been proven to be running stable
during my tests as well, a respective new DRAM config file is added as well.

Signed-off-by: Zoltan HERPAI <wigyori@uid0.hu>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/board/sunxi/Kconfig b/board/sunxi/Kconfig
index 4a6f49f..9a0d8a2 100644
--- a/board/sunxi/Kconfig
+++ b/board/sunxi/Kconfig
@@ -124,6 +124,10 @@
 	bool "IPPO_Q8H_V5"
 	depends on MACH_SUN8I
 
+config TARGET_PCDUINO
+	bool "PCDUINO"
+	depends on MACH_SUN4I
+
 config TARGET_PCDUINO3
 	bool "PCDUINO3"
 	depends on MACH_SUN7I