ARM: dts: msm: Add GPU power level speed bins for SDM670

SDM670 supports multiple GPU power level speed bins.
This change adds all supported GPU power levels speed bins.

Specific speed bin will be used based on efuse value.

Change-Id: Icbdc89ac3a2b5fbed6dbf7cfb7d2dd2c25fb9049
Signed-off-by: Rajesh Kemisetti <rajeshk@codeaurora.org>