msm: kgsl: Add hwcg table for A680

Currently A680 shares hwcg with A640, but A680
has some specific settings in GMU, which address
the MISC GPU hang issue observed on A680 when
enabled pre-emption.

Change-Id: I5b082a37ca4ec2dd92444ceaf6c6828472e8479d
Signed-off-by: Hui Li <hul@codeaurora.org>