Revert "mmc: sdhci: Panic after dumping SDHC registers"

This reverts 'commit d49beb9a2a71 ("mmc: sdhci: Panic
after SDHC registers")'. As CMDQ is quite stable now,
removing a BUG_ON which was added internally to crash
system on error.

Change-Id: Ie0c11743fb781e765c926e3408b87eaf94dc2eb6
Signed-off-by: Sayali Lokhande <sayalil@codeaurora.org>
[subhashj@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>