ASoC: wcd9310: Prevent from going suspend while accessing codec registers

The wcd9310 codec driver which is slimbus slave can access codec
registers when slimbus is suspended.
This can cause register read/write failure.
Fix to make sure slimbus is awake before accessing wcd9310 codec's
registers through slimbus.

CRs-fixed: 331338
Change-Id: Iddbdb1614c18dab4bee4f0cc7951884f34cb7173
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>