hsu: add runtime pm support

Doesn't appear to be much to do here, however having the suspend/resume
functions will allow the d3/d0 transitions to be sent by the pci core.

Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>