USB: host: ohci-at91: add sam9x60-sfr definition for ohci

Add this SFR compatible definition for the sam9x60 SoC and manage
its use in ohci-at91.c driver.

Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>