mmc: core: Fix device hangs issue when inserting bad SD cards

When inserting BAD sdcard in device and trying to read, device status
is continuously in programming state, leading to device hang and black
screen.

There is a 10 minute of waiting for device to come out of programming
state. But 10 minute is too long time to wait and it would increase the
CPU load significantly as we are continuously polling for the card
status.

To fix this issue reduces this timeout from 10 mins to 30 secs which is
quite reasonable for all good cards.

Change-Id: If1d3664a28cc246d8c80a7f0dc115ee7a0f7fd04
Signed-off-by: Ziqi Chen <ziqichen@codeaurora.org>