mmc: msm_sdcc: fix the sdcc version check

MCI_VERSION register has the couple of fields like "major"
and "step". Driver should be checking these fields individually
but at one place we are checking the complete value of MCI_VERSION
register where we should have just checked the "step" field of it.
This change fix it by checking just "step" field instead of entire
MCI_VERSION register value.

Change-Id: If622827b0fc609b6425697c1109ad883cfbb8ad6
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>