msm: kgsl: Migrate SCM calls in adreno

- Migrate iommu_sync scm call to firmware/qcom_scm driver.
- Migrate a5xx_microcode_load to use qcom_scm_set_remote_state.

Change-Id: I05911ac6cf9366b4bff5ee02e6832b8728d1d35e
Signed-off-by: Elliot Berman <eberman@codeaurora.org>