drm/radeon: add radeon_asic struct for CIK (v12)

v2: fix up for latest reset changes
v3: use CP for pt updates for now
v4: update for 2 level PTs
v5: update for ib_parse removal
v6: vm_flush api change
v7: rebase
v8: fix gfx ring function pointers
v9: fix vm_set_page function params
v10: update for compute changes
v11: cleanup for release
v12: update rptr/wptr callbacks

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>