msm: kgsl: Remove nonsense around the a5xx and a6xx SMMU table update

All a5xx and a6xx targets use the CP_SMMU_TABLE_UPDATE opcode to switch the
pagetable which handles all the needed locking but we've seen fit to add a
bunch more around it, including keeping a dummy NOP IB used for
synchronization on a3xx targets.

Stop the madness and remove all the extraneous locking and other baloney
and just do a straight up SMMU_TABLE_UPDATE without fanfare.  And now
that the setstate is only valid for a3xx, only create it for a3xx thereby
removing another global buffer from the mix.

Change-Id: Ic0dedbad7694cad6d40fcee66b7864a454df1653
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>