mmc: sdhci-msm: Correct usage of readl_poll_timeout() API

The intention of sdhci_msm_probe() was to wait up to 1ms for
CORE_SW_RST to be set, but only a 10us timeout was passed to
readl_poll_timeout().

Correct the timeout value to be 1ms, and decrease the sleep
time between read attempts to only 10us so that it's less
than the expected wait time of 40us.

Change-Id: I7007a68232bfba76409e2dbae3060622fa5c1913
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>