ARM: dts: msm: Update GPU SVS plus clock plan for msm8937

As per updated GCC frequency plan GPU SVS Plus clock is 300MHz.
Update GPU SVS plus clock plan to 300MHz to meet the SVS plus
performance request from GPU.

Change-Id: Icdc396c09ab333cc7992f74820946b006f790e07
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>