USB: Rework musb suspend()/resume_early()

This patch reworks platform driver power management code
for musb from legacy callbacks to dev_pm_ops.

The callbacks are converted for CONFIG_SUSPEND like this:
  suspend() -> suspend()
  resume_early() -> resume_noirq()

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>