usb: musb: Simplify PM runtime for 2430 glue layer

With musb core now blocking PM based on the devctl status
bit, we can remove related quirks from the 2430 glue layer
and simplify PM runtime further.

Lets's also use musb->controller instead of dev to make it
clear we make the PM runtime calls for the core, not the
glue layer.

And we can now also lower the autoidle timeout.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Bin Liu <b-liu@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>