CHROMIUM: MALI: fix sysfs memory file

CHROMIUM: MALI: fix sysfs memory file

The sysfs file which reports memory was broken by the recent
update go wk45.

BUG=chromium-os:36060,chrome-os-partner:16814
TEST=Verified that the sysfs file now reports the correct data

localhost ~ # cat /sys/devices/platform/mali.0/memory
57143296 bytes
localhost ~ # stop ui
ui stop/waiting
localhost ~ # cat /sys/devices/platform/mali.0/memory
28672 bytes
localhost ~ # start ui
ui start/running, process 4791
localhost ~ # cat /sys/devices/platform/mali.0/memory
51875840 bytes
localhost ~ # stop ui
ui stop/waiting
localhost ~ # cat /sys/devices/platform/mali.0/memory
28672 bytes

Change-Id: I6df9bf70028ac0bc18fe993242c65dc87c430fd2
Signed-off-by: Mandeep Singh Baines <msb@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/39730
Reviewed-by: Anush Elangovan <anush@google.com>