msm: kgsl: Add GMU version check for new GMU fw init signature

The latest version of GMU firmware will have a new firmware init
signature. In order to have backwards compatibility add a firmware
version check for targets using older firmware.

Change-Id: I6b58fd2872a2cf82ca966fe737defc4889b8a6c7
Signed-off-by: Urvashi Agrawal <urvaagra@codeaurora.org>