p1020rdb-pd: platform support

Add new board p1020RDB-PD. P1020RDB-PD board was update from P1020RDB.
DDR changed from DDR2 1G to DDR3 2G.
NAND: 128 MiB
Flash: 64 MiB

Also change P1020RDB to P1020RDB-PC to distinguish from P1020RDB board.

Signed-off-by: Jerry Huang <Chang-Ming.Huang@freescale.com>
Signed-off-by: Haijun Zhang <Haijun.Zhang@freescale.com>
CC: Scott Wood <scottwood@freescale.com>
Acked-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/p1_p2_rdb_pc/README b/board/freescale/p1_p2_rdb_pc/README
index 4437731..f4cc43f 100644
--- a/board/freescale/p1_p2_rdb_pc/README
+++ b/board/freescale/p1_p2_rdb_pc/README
@@ -3,6 +3,7 @@
 P1_P2_RDB_PC represents a set of boards including
     P1020MSBG-PC
     P1020RDB-PC
+    P1020RDB-PD
     P1020UTM-PC
     P1021RDB-PC
     P1024RDB