ARM: dts: msm: Update GPU power levels for SA6155

Update max GPU frequencies for Nominal and SVS_L1 power levels.

Change-Id: I38a724e82b9081df6e00f4cd6d825ea9c5de6d10
Signed-off-by: Vijayakumar Badiger <vbadig@codeaurora.org>
Signed-off-by: Thomas (Wonyoung) Yun <wyun@codeaurora.org>