pvr: Add support for Am62
This MR enables TI's AM62 platform.
Due to the state of the compiler the triangle demo is not fully functional so it requires non upstreamable binary blobs for the eot usc program and the fragment shader. See frankbinns/mesa@4aea61fa and frankbinns/mesa@6b9157c4 . Note that the new fw will be required as well as those commits to get the triangle running.
This MR is based on top of !16999 (merged) so it contains commits from there. Marking as a draft until that's merged.
Edited by Karmjit Mahil