drm/msm/a6xx: Enable IFPC on Adreno X1-85

Add the IFPC restore register list and enable IFPC support on Adreno
X1-85 gpu.

Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/673384/


Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>