mmc: msm_sdcc: fix possible buffer overflow

If "total_phases" argument of find_most_appropriate_phase()
function have value greater than 16, it may cause the
out bound access for arrays used within this function.

So this patch validates the value of "total_phases" to
avoid buffer overflow.

Change-Id: I0519066b37595e1ee2121b77965b119cfd995eb4
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>