msm: kgsl: Remove support for sparse memory

We are choosing to go in a different direction for virtual buffer objects
so remove the old sparse code to get it out of the way. In a few cases
we'll add back similar code so there is a bit of churn but its easierto
just delete everything and start over from scratch.

This doesn't remove the uapi definitions for sparse since we're stuck
with those forever but they'll just harmlessly return error.

Change-Id: Ic0dedbad9a79ef321e9510115d64b5019743eb2b
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>