drm/amdgpu:divide KCQ mqd init to sw and hw

sw part only invoked once during sw_init.
hw part invoked during first drv load and resume later.

that way we cannot alloc mqd in hw/resume, we only keep
mqd allocted in sw_init routine.
and hw_init routine only kmap and set it.

Signed-off-by: Monk Liu <Monk.Liu@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>