USB: update gadget files for fsl_usb2_udc driver

Update gadget_chip.c, ether.c for newly added Freescale Highspeed USB
device driver.

Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>