msm: kgsl: Remove references to adreno_regs from target specific code

The adreno_regs are supposed to used to do register offset lookups from
generic code.  Since the target specific code already knows the register
offset it wants the lookup step is unessesary.

Change-Id: Ic0dedbad839e75006078b6d29ee99179a6680ade
Signed-off-by: Jordan Crouse <jcrouse@codeaurora.org>