msm: kgsl: Force all command level context switches to the GPU

Force any command triggered context switch to the GPU - it should
be on the GPU anyway, but we were already passing a flags parameter
(unused) so this is a good chance to force the issue and make sure
that the cpu path decision isn't in play here.

Change-Id: Ic0dedbadb277a6498d0840b45c90e1265e2f354a
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>