msm: kgsl: Cleanup the memory free list

Tighten up the memory free list code and remove the memory unused
debugfs file.  Outside of the cleanup the functional changes are
a) move the mutex to a spinlock for speed, and b) only return the
last entry in the list for given pid/gpu address combination.

Conflicts:
	drivers/gpu/msm/kgsl.c
	drivers/gpu/msm/kgsl.h
	drivers/gpu/msm/kgsl_debugfs.c

Change-Id: Ic0dedbad9595302e2b42de2807fa82c425d1717f
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
Revert "msm: kgsl: Changing to kref_get_unless_zero for process refcount"

This reverts commit f031a515dec023a21f0b824e81a8d8d5fe8b77e8.
msm: kgsl: hold a process_private refcount in process_mem_print

There is a possible race condition where the process can be going
away while its debugfs 'mem' file is being read, which could cause
memory corruption.

Conflicts:

	drivers/gpu/msm/kgsl.c

CRs-Fixed: 627780
Change-Id: I697486faeb3f186fd1220d0acc1e449a4f7b77b0
Signed-off-by: Jeremy Gebben <jgebben@codeaurora.org>
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>
Build v3.98.1 EXP4