msm: kgsl: Return error from adreno_llc_getd() stub

Return error from adreno_llc_getd() stub in case CONFIG_QCOM_LLCC
is not defined. Currently, it is returning NULL, which is resulting
in driver configuring GPU, GPUHTW SCID and setting iommu domain
attributes which is not desired in LLCC disabled case.

Change-Id: I2b90c1b62d70f117a2974549242aef11826ef364
Signed-off-by: Deepak Kumar <dkumar@codeaurora.org>