Revert "gralloc: Fix PMEM heap allocation for 3.0 kernels"

This reverts commit 7ad223213d91e5afad750ecbc35908138c67d572.
gralloc: Fix PMEM heap allocation for 3.0 kernels

This is needed for PMEM camera libraries.

Symptoms: gralloc gives an error saying invalid argument to map /dev/pmem_adsp, and dmesg says that ION is trying to mmap it. This issue is likely being caused by the ION drivers in the 3.0 kernel as this issue does not exist with 3.4 kernels.

Signed-off-by: Sultanxda <sultanxda@gmail.com>