defconfig: msm: Enable ZRAM support for msm8916

ZRAM can help system serve better under memory
high pressure by creating compressed block device
in RAM which acts as swap space.

Change-Id: Ie39a0d9bab232cebd0ebdb0c2059cf6a7e3231f7
Signed-off-by: Susheel Khiani <skhiani@codeaurora.org>