drm/v3d: Fix and extend MMU error handling.

drm/v3d: Fix and extend MMU error handling.

We were setting the wrong flags to enable PTI errors, so we were
seeing reads to invalid PTEs show up as write errors.  Also, we
weren't turning on the interrupts.  The AXI IDs we were dumping
included the outstanding write number and so they looked basically
random.  And the VIO_ADDR decoding was based on the MMU VA_WIDTH for
the first platform I worked on and was wrong on others.  In short,
this was a thorough mess from early HW enabling.

Tested on V3D 4.1 and 4.2 with intentional L2T, CLE, PTB, and TLB
faults.

Signed-off-by: Eric Anholt <eric@anholt.net>
Link: https://patchwork.freedesktop.org/patch/msgid/20190419001014.23579-4-eric@anholt.net
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>