dmabuf_dump: Change the default view to per-process stats

Add '-a' commandline option to show the old complete table that shows
dmabuf x process grid.

Fixes: 135668399
Test: dmabuf_dump
Test: dmabuf_dump -h
Test: dmabuf_dump -a
Test: dmabuf_dump -a 123
Test: dmabuf_dump 123 456
Test: dmabuf_dump <pid>

Change-Id: If228c97baa375c515d94baf3b5be674cfcc09919
Merged-In: If228c97baa375c515d94baf3b5be674cfcc09919
Signed-off-by: Sandeep Patil <sspatil@google.com>