Add missing pieces for PRIV_FLAGS_USES_PMEM_SMI flag

Signed-off-by: Sultanxda <sultanxda@gmail.com>
libgralloc: Rename USE_PMEM_ADSP to USE_PMEM_CAMERA

This flag enables PMEM SMI and PMEM ADSP, not just PMEM ADSP.
libgralloc: Remove PMEM SMI

Videos weren't playing back with PMEM SMI so there is no need for it anymore.
gralloc: Inherit ION definitions from kernel

WHO PUT ION_MSM.H HERE?! GAH!
framebuffer: Use 3 buffers

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