mmc: sdhci: cast unsigned int to unsigned long long to avoid unexpeted error

Potentially overflowing expression 1000000 * data->timeout_clks with
type unsigned int is evaluated using 32-bit arithmetic, and then used
in a context that expects an expression of type unsigned long long.

To avoid overflow, cast 1000000U to type unsigned long long.
Special thanks to Coverity.

Fixes: 7f05538a

 ("mmc: sdhci: fix data timeout (part 2)")
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org # v3.15+
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>