mx28: Let dram_init be common for mx28

Let dram_init function be a common function, so that other mx28 boards
can reuse it.

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Acked-by: Marek Vasut <marek.vasut@gmail.com>
diff --git a/board/denx/m28evk/m28evk.c b/board/denx/m28evk/m28evk.c
index 005446a..53df476 100644
--- a/board/denx/m28evk/m28evk.c
+++ b/board/denx/m28evk/m28evk.c
@@ -70,25 +70,9 @@
 	return 0;
 }
 
-#define	HW_DIGCTRL_SCRATCH0	0x8001c280
-#define	HW_DIGCTRL_SCRATCH1	0x8001c290
 int dram_init(void)
 {
-	uint32_t sz[2];
-
-	sz[0] = readl(HW_DIGCTRL_SCRATCH0);
-	sz[1] = readl(HW_DIGCTRL_SCRATCH1);
-
-	if (sz[0] != sz[1]) {
-		printf("MX28:\n"
-			"Error, the RAM size in HW_DIGCTRL_SCRATCH0 and\n"
-			"HW_DIGCTRL_SCRATCH1 is not the same. Please\n"
-			"verify these two registers contain valid RAM size!\n");
-		hang();
-	}
-
-	gd->ram_size = sz[0];
-	return 0;
+	return mx28_dram_init();
 }
 
 #ifdef	CONFIG_CMD_MMC