board/p1010rdb:Add NAND boot support using new SPL format

- defines constants
  - Add spl_minimal.c to initialise DDR
  - update TLB entries as per NAND boot
  - remove nand_spl support for P1010RDB

Signed-off-by: Prabhakar Kushwaha <prabhakar@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>