msm: kgsl: convert some workqueues to use kthreads.

adreno_dispatch_work and _kgsl_event_worker are both low-latency
low-runtime functions that are in the critical path of GPU
rendering. Moving them out of workqueues and into a dedicated FIFO
kthread avoids significant jitter.

bug 30342017

Git-commit: 1a7a93bd33f48a369de29f6f2b56251127bf6ab4
Git-repo: https://android.googlesource.com/kernel/msm



Change-Id: I83562f488c34c2ab001c8ea79e7f09b633c658bd
Signed-off-by: Tim Murray <timmurray@google.com>
Signed-off-by: Abhilash Kumar <krabhi@codeaurora.org>