mmc: incomplete test to switch to high-capacity group size definitions

mmc: incomplete test to switch to high-capacity group size definitions

The eMMC spec mandates that the high-capacity group size definitions
should be enabled when the device is partitioned (by setting
ERASE_GROUP_DEF in EXT_CSD). The current test to determine when this is
required misses a few cases. In particular a device may have been
partitioned without setting the enhanced attribute on any partition
or partitioning may be completed without creating any extra partitions.

This change moves the code to set ERASE_GROUP_DEF to after reading
all partition information. It is also enabled when
PARTITIONING_SETTING_COMPLETED is set as it is necessary to enable
ERASE_GROUP_DEF before setting that bit, so it means that the user
previously switched to the high capacity definitions.

Signed-off-by: Diego Santa Cruz <Diego.SantaCruz@spinetix.com>