drm/msm: switch to qti KGSL driver

DRM msm driver has option to switch between
qti kgsl driver and drm GPU driver. Qti kgsl
driver is preferred over other driver to support
rendering because it supports all qti features
with custom optimization. This change allows
to select qti kgsl driver if it is available.

Conflicts:
	drivers/gpu/drm/msm/msm_drv.c

Change-Id: I031eeec6378b6ce436c09c1a8388401e7ff48f52
Signed-off-by: Stephane Viau <sviau@codeaurora.org>
Signed-off-by: Dhaval Patel <pdhaval@codeaurora.org>
[narendram@codeaurora.org: resolve msm_drv.c conflict]
Signed-off-by: Narendra Muppalla <narendram@codeaurora.org>