mfd: wcd9xxx: Fix codec hardware reset sequence

The wcd9k codec hardware's reset is held since system boots to make sure
hardware is in reset during enabling regulators.
But current codec driver toggles reset which results in resetting twice.
Fix reset sequence so hardware can get reset only once.

Change-Id: I5a84e57d48ea991864db3e65f995a321f645e66b
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>