mmc: core: reduce the maximum timeout for BKOPs

Currently we have 4 mins timeout for the blocking bkops to be completed
but we have seen instances where card is surprisingly taking even more
time to complete their bkops operations. So if we let the card take
more than 4 mins then it would affect the user experience if user tries
to launch some application (or any other user operation resulting in
read from the card) while card is busy doing BKOPs.

User experience is most important aspect so we are reducing the maximum
BKOPs timeout to max 30 secs and if card doesn't complete the BKOPs in
the timeout specified above, we will send the HPI command to interrupt
the on going BKOPs.

Change-Id: I14355fb79979058f388cd726091752797c316503
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
(cherry picked from commit 188b2a8723b4728c7c0c4c445e1aefe6e42895c9)