drm/amdkfd: Change MQD manager to be H/W specific

The MQDs for CI and VI are different. Therefore, the MQD manager module need to
be H/W specific.

This patch splits the current MQD manager into three files:

- kfd_mqd_manager.c, which contains common functions and initializes the
  specific mqd manager module according to the H/W

- kfd_mqd_manager_cik.c, which contains Kaveri specific functions. This is
  basically the old kfd_mqd_manager.c

- kfd_mqd_manager_vi.c, which will contain VI specific functions. Currently it
  is not implemented except for returning NULL on initialization.

Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>