ASoC: wcd9306: remove runtime PM voting

All the codec reads/writes go through slimbus satellite driver on APPS.
Slimbus satellite driver is already voting for slimbus clock before any
codec read or write so remove the vote from codec driver

Change-Id: I61f5b22d14f87668766d8d2f948a087066a73b11
Signed-off-by: Laxminath Kasam <lkasam@codeaurora.org>