clk: msm: clock-gcc-8952: Add 300MHz clock frequency to GFX3D

GFX3D clock requires 300MHz clock frequency support, also update the VCO
mode of the PLL to 1 to support all the required frequencies.

Change-Id: If42e42016b132726e831d31bf3f9dbcebefdaa56
Signed-off-by: Taniya Das <tdas@codeaurora.org>