lib: Add debugfs file for tracking memory allocations

Add caller information to memory allocation calls and
create /sys/kernel/debug/mempool/map to show the current set of
allocations across all memory pools.

Change-Id: I0f3613158595a3a12837c46dfe500e2e3fea57b9
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>
(cherry picked from commit 9081938c99b91c714316d6fa3a6618ab27789dc7)

Conflicts:

	arch/arm/mach-msm/memory.c