powerpc/85xx: Add support to save environment in SD card on p1_p2_rdb

If we boot from a SD card use it for the environment as well.

Signed-off-by: Priyanka Jain <Priyanka.Jain@freescale.com>
Signed-off-by: Poonam Aggrwal <Poonam.Aggrwal@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
1 file changed