msm: kgsl: Add arch_mmap_check() stub definition

Add a stub definition for arch_mmap_check() in kgsl.c for
situations where the function is not defined, similar to the
stub definition in mm/mmap.c

Change-Id: I2d0f7f8c76f35cbec1554893433199e256f76df4
Signed-off-by: Shrenuj Bansal <shrenujb@codeaurora.org>
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>
msm: kgsl: Fix the NULL context submission size

When submitting commands with a NULL context the size may not be
calculated properly. Fix this calculation.

Change-Id: Idcc37772349673da8a9b9d5127f88946ced8fff6
Signed-off-by: Lynus Vaz <lvaz@codeaurora.org>