ASoC: msm8x16-wcd: check on array index for out of bound access

There is a crash because of out of array access. So add a
check for array index to be lesser than the array size.

CRs-Fixed:997199
Change-Id: Id1a21f19fdc28be4bb80b85e71e3338c9126ec6b
Signed-off-by: dojha <dojha@codeaurora.org>