drm/amdkfd: fix vmfault signalling with additional data.

Exception handling for vmfaults should be raised with additional data.

Reported-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Jonathan Kim <jonathan.kim@amd.com>
Reviewed-by: Mukul Joshi <mukul.joshi@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>