drm/amdkfd: Add gfx11 trap handler

Based on gfx10 with following changes:

- GPR_ALLOC.VGPR_SIZE field moved (and size corrected in gfx10)
- s_sendmsg_rtn_b64 replaces some s_sendmsg/s_getreg
- Buffer instructions no longer have direct-to-LDS modifier

Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Reviewed-by: Laurent Morichetti <laurent.morichetti@amd.com>
Signed-off-by: Eric Huang <jinhuieric.huang@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>