drm/radeon: add get_allowed_info_register function for r1xx-r5xx
drm/radeon: add get_allowed_info_register function for r1xx-r5xx

Just a stub.

Tested-by: Marek Olšák <8c7344a1abdb103e79ecfd488098373070c3c70e@amd.com>
Signed-off-by: Alex Deucher <08dc22c6156113f2deff178e35e3ed9b24d6af9e@amd.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs