msm: kgsl: Add support for primitive threshold value

The primitve threshold value is different for almost every
chip, so instead of using a whole lot of if else, use the
gpu feature list to specify its value.

Change-Id: I020e4237e0f965f3816a640cde2f33659e6192ca
Signed-off-by: Urvashi Agrawal <urvaagra@codeaurora.org>