msm/adreno: Don't mark KGSL scratch buffer as privileged

Partial revert of commit 7d0fd9e6, especially on adreno_ringbuffer_probe()
where marking the scratch buffer as privileged currently breaks all devices.

I'm assuming that this change requires updated Adreno firmware, which most of
us don't have. All changes required to marking it so are retained, however.

Signed-off-by: Albert I <kras@raphielgang.org>
Change-Id: Ibd684b8a47ed3bdf1fad60dd3df8c4dab01644a1
Signed-off-by: danascape <saalimquadri1@gmail.com>
Signed-off-by: danascape <danascape@gmail.com>