powerpc: p1022ds: Enable P1022DS to boot from SD Card with SPL

Enable p1022ds to start from eSDHC with SPL.

Signed-off-by: Ying Zhang <b40530@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>
diff --git a/README b/README
index 301d1a9..18f5233 100644
--- a/README
+++ b/README
@@ -3094,6 +3094,10 @@
 		Set for the SPL on PPC mpc8xxx targets, support for
 		arch/powerpc/cpu/mpc8xxx/ddr/libddr.o in SPL binary.
 
+		CONFIG_SPL_COMMON_INIT_DDR
+		Set for common ddr init with serial presence detect in
+		SPL binary.
+
 		CONFIG_SYS_NAND_5_ADDR_CYCLE, CONFIG_SYS_NAND_PAGE_COUNT,
 		CONFIG_SYS_NAND_PAGE_SIZE, CONFIG_SYS_NAND_OOBSIZE,
 		CONFIG_SYS_NAND_BLOCK_SIZE, CONFIG_SYS_NAND_BAD_BLOCK_POS,