msm: kgsl: Remove A2XX support

All targets supporting A2XX GPUs were removed from the kernel in
b3270aa98aa7f4d7ccf1eef10e0624409dfe415f. If we left A2XX code
in KGSL it would bitrot that much faster. Farewell old friend.

Change-Id: Ic0dedbad7d31ab1c30e1fabf4f10f867a73299dc
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>

Conflicts:
	drivers/gpu/msm/adreno_a2xx.c