uboot-imx

mmc: fix ERASE_GRP_DEF handling

if we set manually this bit on the eMMC card using mmc_switch(...),
we also have to set it within our (before read) internal structure
'ext_csd'.

Otherwise following checks on this will fail.

Acked-by: Pantelis Antoniou <panto@antoniou-consulting.com>
Signed-off-by: Hannes Petermaier <oe5hpm@oevsv.at>