msm/drm: Move msm_drm_config configuration into the GPUs

msm/drm: Move msm_drm_config configuration into the GPUs

With the upcoming secure code the decision tree for configuration
(deciding where virtual addresses start/stop, etc) is going to get
a bit more complex. Head issues off at the pass by moving the
configuration into the GPU specific code.  This does result in a
bit more code duplication but it is a lot cleaner.

Change-Id: Ic0dedbad57c11a4bba01825214d0a7853ab537ba
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>