msm: kgsl: Make sure USE_CPU_MAP + MAP_USER_MEM work together

If one is mapping anonyomous user memory in the GPU with SVM enabled
we want to try to accommodate that request if possible. The memory
address was being set up correctly in the memory descriptor but
the GPU address was getting tripped up when getting mapped in the
process.  This is because the memory should be treated like SVM
memory so it needs to be registered in the memory tree and the
rest of the path needs to accept the address.

Change-Id: Ic0dedbad661143977a226d50263c26b5af579ce3
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>