Squash revert of two mmc commits

Revert "mmc: block: reduce the block timeout to 30 secs"
Revert "mmc: core: Fix some driver hangs when dealing with broken devices"

This fixes the boot up crashes on d2

This reverts commits 9de653e499abd536a89e119c6e84bf08d2777579 and b4046456a04c2e621decff40249b75b856c31285

Change-Id: I2933ba7d3545f0d108110c881dcf6963e4ffbbf6
Merge "Squash revert of two mmc commits" into cm-11.0