Three compatible strings have been added to the at91_udc driver.
Update the documentation accordingly.
Signed-off-by: NBoris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: NAlexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: NNicolas Ferre <nicolas.ferre@atmel.com>