mmc: sdhci: use cmd_timeout_ms for calculating request timeout

For some of the SD/MMC cards like erase, sanitize etc, the
maximum timeout will be specified by cmd_timeout_ms parameter
(as defined by specification). For such commands, the host
driver must use this value instead of always using the default
request timeout value of 10sec.

Change-Id: I5b13379df3d260513be675a8585479ad5672662b
Signed-off-by: Sahitya Tummala <stummala@codeaurora.org>