Redirect invalid memory accesses to the default page
instead of locking up the memory controller.

v2: rebase on top of 2 level PTs
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

The vm callbacks are the same as the SI ones right now
(same regs and bits). We could share the SI variants, and
I may yet do that, but I figured I would add CIK specific
ones for now in case we need to change anything.

V2: add documentation, minor fixes.
V3: integrate vram offset fixes for APUs
V4: enable 2 level VM PTs
V5: index SH_MEM_* regs properly
V6: add ib_parse()
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

v2: split soft reset into compute and gfx.  Still need
to make reset more fine grained, but this should be a
start.
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>

v2: tiling fixes
v3: more tiling fixes
v4: more tiling fixes
v5: additional register init
v6: rebase
v7: fix gb_addr_config for KV/KB
v8: drop wip KV bits for now, add missing config reg
v9: fix cu count on Bonaire
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>