arm: marvell: Move arch/kirkwood.h to arch/soc.h

This move makes is possible to use this header not only from kirkwood
platforms but from all Marvell mvebu platforms.

Signed-off-by: Stefan Roese <sr@denx.de>
Tested-by: Luka Perkov <luka@openwrt.org>
Acked-by: Prafulla Wadaskar <prafulla@marvell.com>
diff --git a/arch/arm/cpu/arm926ejs/kirkwood/cpu.c b/arch/arm/cpu/arm926ejs/kirkwood/cpu.c
index 881e2de..75d3799 100644
--- a/arch/arm/cpu/arm926ejs/kirkwood/cpu.c
+++ b/arch/arm/cpu/arm926ejs/kirkwood/cpu.c
@@ -12,7 +12,7 @@
 #include <u-boot/md5.h>
 #include <asm/io.h>
 #include <asm/arch/cpu.h>
-#include <asm/arch/kirkwood.h>
+#include <asm/arch/soc.h>
 #include <mvebu_mmc.h>
 
 #define BUFLEN	16