msm: kgsl: Don't restrict compat tasks to 32-bit VA range

We were restricting the GPU VA on compat tasks to 32-bits. However,
in principle, there is no reason to constrain non-SVM allocations
and mappings to this range as long as userspace uses the appropriate
IOCTLs that support larger GPU VAs.

Change-Id: I2f3e52021d81957c1c848acbd5f2caa965745a86
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>