drm/amdkfd: Enable atomic support for GFX12

Enable flag in KFD and set the atomic support bit in MQD.

Signed-off-by: David Belanger <david.belanger@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>