CM4000: fix missing RAM definitions for OpenGear boards

The OpenGear boards CM4008, CM4116 and CM4148 need their DRAM base
and RAM stack base addresses defined.

Fixes:

board.c: In function ‘__dram_init_banksize’:
board.c:227: error: ‘CONFIG_SYS_SDRAM_BASE’ undeclared (first use in this function)
board.c:227: error: (Each undeclared identifier is reported only once
board.c:227: error: for each function it appears in.)
board.c: In function ‘board_init_f’:
board.c:270: error: ‘CONFIG_SYS_INIT_SP_ADDR’ undeclared (first use in this function)
board.c:303: error: ‘CONFIG_SYS_SDRAM_BASE’ undeclared (first use in this function)

Signed-off-by: Greg Ungerer <greg.ungerer@opengear.com>
diff --git a/include/configs/cm41xx.h b/include/configs/cm41xx.h
index dca7d54..785ab0a 100644
--- a/include/configs/cm41xx.h
+++ b/include/configs/cm41xx.h
@@ -114,6 +114,9 @@
 #define CONFIG_NR_DRAM_BANKS	1	   /* we have 1 bank of DRAM */
 #define PHYS_SDRAM_1		0x00000000 /* SDRAM Bank #1 */
 #define PHYS_SDRAM_1_SIZE	0x02000000 /* 32 MB */
+#define CONFIG_SYS_SDRAM_BASE	PHYS_SDRAM_1
+
+#define CONFIG_SYS_INIT_SP_ADDR	0x00020000 /* lowest 128k of RAM */
 
 #define PHYS_FLASH_1		0x02000000 /* Flash Bank #1 */
 #define PHYS_FLASH_SECT_SIZE    0x00020000 /* 128 KB sectors (x1) */