msm: kgsl: Fix incorrect parameter when calling calc_gmemsize.

While calculating GMEM size, passing gmem_base for gmem_size
causes rendering problems. Pass gmem_size for correct
rendering.

Change-Id: I1ecec9ab5928d9d205d1d312298da813337c2053
Signed-off-by: Anoop Kumar Yerukala <ayeruk@codeaurora.org>