msm: kgsl: Move gmu_init from gmu_start to adreno_init

When request_firmware for gmu_fw fails, we set kgsl state to
KGSL_STATE_RESET. During this process gmu_fw_start gets called
and it tries to load gmu fw resulting in null pointer access.

Moving gmu_init() from gmu_start() to adreno_init(). This will
avoid unnecessary state changes when request_firmware for
gmu_fw fails.

Change-Id: I8d4e9f8b4c8a38c7303d4c71f3e4d47a6b110056
Signed-off-by: Pankaj Gupta <gpankaj@codeaurora.org>