mmc: sdhci: Panic after dumping SDHC registers

eMMC CMDQ is pretty latest feature and we may continue to see issues
due to HW & SW immaturity. To debug these issues, we should have the
host controller register dumps along with current SW state from rampdumps.
This change adds the BUG_ON to crash the system in case of eMMC related
command timeouts.

Change-Id: Ib832aef6eb9ef3941fbe9e73852929c835e97847
Signed-off-by: Venkat Gopalakrishnan <venkatg@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>