msm: kgsl: Defer issue commands to worker thread

Currently submit ioctl getting blocked till the commands
gets added to ringbuffer incase inflight count is less
than context burst count. If the submit command happens
in GPU slumber state, it will add the GPU wakeup time to
submit IOCTL. This will add latency in preparing next frame
in CPU side. Defer commands submission to dispatcher worker,
if the GPU is in slumber state.

CRs-Fixed: 2055107
Change-Id: I099ba721e02bbcd8ccadb1bc518c7c1ef4fb7e21
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>