msm: kgsl: Bring in the GPU bandwidth governor

Add a copy of the Adreno GPU bandwidth governor from msm-4.19 as of
01dafb76 ("Merge "power: qpnp-qnovo5: Add standalone class param"")

Like the GPU frequency governor, move it to the KGSL driver directory
to share local headers.

Change-Id: Ic0dedbadbdeef532a3e847db759b9840282064da
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>