powerpc/t2080rdb: update ddr to support 1866MT/s

Support SODIMM D3XP12081XL10AA 1866MT/s on T2080RDB.
Enable CONFIG_CMD_MEMTEST as well.

Signed-off-by: Shengzhou Liu <Shengzhou.Liu@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/include/configs/T208xRDB.h b/include/configs/T208xRDB.h
index 453cb88..a3d06c4 100644
--- a/include/configs/T208xRDB.h
+++ b/include/configs/T208xRDB.h
@@ -140,6 +140,11 @@
 #define CONFIG_MEM_INIT_VALUE		0xdeadbeef
 #endif
 
+#define CONFIG_CMD_MEMTEST
+#define CONFIG_SYS_MEMTEST_START	0x00200000 /* memtest works on */
+#define CONFIG_SYS_MEMTEST_END		0x00400000
+#define CONFIG_SYS_ALT_MEMTEST
+
 #ifndef CONFIG_SYS_NO_FLASH
 #define CONFIG_FLASH_CFI_DRIVER
 #define CONFIG_SYS_FLASH_CFI