msm: kgsl: Remove cpu_is_msm8960() check

The check in the code will always evaluate to true now that we
don't support A-family and does not affect the if statement that
uses it.

Change-Id: Ifdf88cc0305eb64a6a50f72a23e69239173ee4c6
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>