msm: kgsl: Free the memory allocated for pages array in failure case

kgsl_system_alloc_pages and kgsl_pool_alloc_pages allocate memory for
pages array. This memory is not freed in kgsl_alloc_secure_pages in
some failure cases. Free the allocated memory in case of failure to
avoid memory leak issues.

Change-Id: Ifed2573506d549f60d01f8d3ba06cbabdc9878e0
Signed-off-by: Puranam V G Tejaswi <pvgtejas@codeaurora.org>