mxs: Rename 'mx28_dram_init' to 'mxs_dram_init'

The DRAM initialization, after SPL has complete, is exactly the same
for all mxs SoCs so we should name it accordinly.

The following boards has been changed:

 * apx4devkit
 * m28evk
 * mx28evk
 * sc_sps_1
Signed-off-by: NOtavio Salvador <otavio@ossystems.com.br>
Acked-by: NMarek Vasut <marex@denx.de>
Acked-by: NVeli-Pekka Peltola <veli-pekka.peltola@bluegiga.com>

arch/arm/cpu/arm926ejs/mxs/mxs.c

@@ -320,13 +320,13 @@ void imx_get_mac_from_fuse(int dev_id, unsigned char *mac)
 }
 #endif
 
-int mx28_dram_init(void)
+int mxs_dram_init(void)
 {
 	struct mxs_spl_data *data = (struct mxs_spl_data *)
 		((CONFIG_SYS_TEXT_BASE - sizeof(struct mxs_spl_data)) & ~0xf);
 
 	if (data->mem_dram_size == 0) {
-		printf("MX28:\n"
+		printf("MXS:\n"
 			"Error, the RAM size passed up from SPL is 0!\n");
 		hang();
 	}

arch/arm/include/asm/arch-mxs/sys_proto.h

@@ -69,6 +69,6 @@ struct mxs_spl_data {
 	uint32_t	mem_dram_size;
 };
 
-int mx28_dram_init(void);
+int mxs_dram_init(void);
 
 #endif	/* __SYS_PROTO_H__ */

board/bluegiga/apx4devkit/apx4devkit.c

@@ -55,7 +55,7 @@ int board_early_init_f(void)
 
 int dram_init(void)
 {
-	return mx28_dram_init();
+	return mxs_dram_init();
 }
 
 int board_init(void)

board/denx/m28evk/m28evk.c

@@ -72,7 +72,7 @@ int board_init(void)
 
 int dram_init(void)
 {
-	return mx28_dram_init();
+	return mxs_dram_init();
 }
 
 #ifdef	CONFIG_CMD_MMC

board/freescale/mx28evk/mx28evk.c

@@ -64,7 +64,7 @@ int board_early_init_f(void)
 
 int dram_init(void)
 {
-	return mx28_dram_init();
+	return mxs_dram_init();
 }
 
 int board_init(void)

board/schulercontrol/sc_sps_1/sc_sps_1.c

@@ -72,7 +72,7 @@ int board_init(void)
 
 int dram_init(void)
 {
-	return mx28_dram_init();
+	return mxs_dram_init();
 }
 
 #ifdef	CONFIG_CMD_MMC