Set GPU LIGHT clk divider ratios to /2.
Bug: 327700285
Test: Confirm no prints like:
"28000000.mali: Ctx 8349_23 Group 0 CSG 3 CSI: 3"
while running GFXBench under LIGHT MITIGATION
Change-Id: I4b62b33c0b72e5a053f477943379727d58f7298e
Signed-off-by: George Lee <geolee@google.com>