clk: qcom: gpucc: Update the PLL 2x frequency

The GPUCC PLL needs to lock at 2x the RCG frequency, thus update the RCG
divider to '2' to lock the PLL at 2x.

Change-Id: Iadeb8b03cf10c170efa8b11bf9aadc35f67ce736
Signed-off-by: Taniya Das <tdas@codeaurora.org>