ARM: dts: msm: Add initial-powerlevel for speedbin config of MSM8917

Initial powerlevel is not defined for speedbin configuration.
This will cause GPU to wake up at default power level NOM+
instead of SVS+. Add initial-powerlevel for MSM8917 GPU
to wakeup at SVS+.

CRs-Fixed: 1068696
Change-Id: I1606667e3b36c0d1d4ffd5922459aad49612a8cf
Signed-off-by: Hareesh Gundu <hareeshg@codeaurora.org>