usb: dwc: remove "All rights reserved" statement.

Some people think that this line is not compatible with the GPL. The
statement was required due to the Buenos Aires Convention and is now
deprecated. I remove it because it is said that it is pointless nowdays.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>