This is needed in preparation of adding support for omap3 and
later OHCI. The runtime PM will only do something on platforms
that implement it.

Cc: devicetree@vger.kernel.org
Cc: Hans de Goede <hdegoede@redhat.com>
Cc: Rob Herring <robh@kernel.org>
Cc: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Cc: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Acked-by: Roger Quadros <rogerq@ti.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>