Revert "drm/radeon: Report doorbell configuration to amdkfd"

This reverts commit ebff8453. Unused
since amdkfd is no longer supported with radeon.

Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>