msm: kgsl: Move the IOMMU clocks to the KGSL device

Move ownership of the IOMMU clocks to the KGSL device and get them from
there during IOMMU probe.  This ensures that the clocks are owned by a
proper platform device that can sync_state() after we are done probing.

Change-Id: Ic0dedbad97783984f7d8d1c3c2252a1a8a812d77
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>