drm/amdkfd: Support Navi14 in KFD

Initial support of Navi14 in KFD. The device IDs will be added later.

Signed-off-by: Yong Zhao <Yong.Zhao@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>