M28: Add memory detection into SPL

This code allows the DDR DRAM size to be detected at runtime. The RAM size is
stored into two scratch registers, from which it is then fetched in U-Boot.

Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
diff --git a/include/configs/m28evk.h b/include/configs/m28evk.h
index 381b01e..c8b0cf5 100644
--- a/include/configs/m28evk.h
+++ b/include/configs/m28evk.h
@@ -81,7 +81,7 @@
  */
 #define	CONFIG_NR_DRAM_BANKS		1		/* 2 banks of DRAM */
 #define	PHYS_SDRAM_1			0x40000000	/* Base address */
-#define	PHYS_SDRAM_1_SIZE		0x08000000	/* 128 MB */
+#define	PHYS_SDRAM_1_SIZE		0x40000000	/* Max 1 GB RAM */
 #define	CONFIG_STACKSIZE		0x00010000	/* 128 KB stack */
 #define	CONFIG_SYS_MALLOC_LEN		0x00400000	/* 4 MB for malloc */
 #define	CONFIG_SYS_GBL_DATA_SIZE	128		/* Initial data */