mmc: sdhci: Use max timeout and skip timeout calculation

Several data-timeout issues were seen, most of which were
due to the card taking a longer time to respond. This patch
increases the timeout of the controller to 0xF i.e. max
possible.

Change-Id: I6739de3eb5d9cccf8e39d9dc4730056782334162
CRs-Fixed: 536832
Signed-off-by: Asutosh Das <asutoshd@codeaurora.org>