msm: kgsl: Add support for enhanced memory accounting

Update the vm_stat counter NR_UNRECLAIMABLE_PAGES to account for
the total memory allocated. Update the rss_stat counter MM_UNRECLAIMABLE
to account for the memory allocated and memory imported per process.

Change-Id: I0a40bf215fedbe421cce8d5fc41e2580fefb6523
Signed-off-by: Puranam V G Tejaswi <pvgtejas@codeaurora.org>