msm: kgsl: Disable dynamic gmem clk gating for MSM8939

Disable dynamic gmem clock gating for 8939 and its
variants to ensure forward compatability with V3.0

Change-Id: Iebdf196a660bab60628ec1011749ddf1e4e5ff50
Signed-off-by: Anshuman Dani <adani@codeaurora.org>
Signed-off-by: Sridhar Gujje <sgujje@codeaurora.org>
Signed-off-by: Bharat Pawar <bpawar@codeaurora.org>
Signed-off-by: Nirmal Abraham <nabrah@codeaurora.org>