ASoC: msm8x10: fix missing iounmap after ioremapped memory

If ioremap is used, iounmap has to be called. Missing iounmap call
cause flooding vmalloc table which will end up with random crashes.

CRs-fixed: 502923
Change-Id: I7fd9bc1367ef50afe9b586e66c014f4af677bc4e
Signed-off-by: Fred Oh <fred@codeaurora.org>