i.MX28: Move SPL to arch/arm/cpu/arm926ejs/mx28

This moves SPL to common location so it can be reused by multiple boards. Also,
this commit adjusts M28 SoM to avoid breakage due to the move.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
diff --git a/include/configs/m28evk.h b/include/configs/m28evk.h
index d4bd207..cdf7636 100644
--- a/include/configs/m28evk.h
+++ b/include/configs/m28evk.h
@@ -48,8 +48,8 @@
  */
 #define	CONFIG_SPL
 #define	CONFIG_SPL_NO_CPU_SUPPORT_CODE
-#define	CONFIG_SPL_START_S_PATH		"board/denx/m28evk"
-#define	CONFIG_SPL_LDSCRIPT		"board/denx/m28evk/u-boot-spl.lds"
+#define	CONFIG_SPL_START_S_PATH		"arch/arm/cpu/arm926ejs/mx28"
+#define	CONFIG_SPL_LDSCRIPT	"arch/arm/cpu/arm926ejs/mx28/u-boot-spl.lds"
 
 /*
  * U-Boot Commands