ARM: dts: msm: Limit max gpu power level jump for MSM8940

Restrict max power level jump to 1, during the GPU clock
switch and while coming out from slumber. This will address
the device stability issue.

CRs-Fixed: 1110516
Change-Id: I93f0e3022832c25c0fe1a48c5709ebfbd07249a0
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>