msm: kgsl: Return the raw chipid in kgsl_gpuid

There are some subtle differences between revisions of GPUs
that are not reflected in the GPU ID value. Return the raw
chipid (derived from the hardware) along with the GPU ID
when queried.

Change-Id: Ic0dedbad035a80726e6fedc066ec11b78b79da2b
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>