drm/msm/sde : initialize rsc_state and wait_refcount

Initialize rsc_state to idle_state and wait_refcount
to zero before using the variables.

Change-Id: Iddcb5ca26ebaeaac1c41f82706f96b088193c8ac
Signed-off-by: Jayaprakash <jmadiset@codeaurora.org>