usb: host: ohci: fix sfr kernel warning in ohci-at91 driver

The USB Host Controller driver 'ohci-at91.c' reads a Special Function
Register - OHCI Interrupt Configuration Register (AT91_SFR_OHCIICR)
for bits SUSPEND_A/B/C. These bits are defined in sama5d2 alone, so
sfr register mapping is done with compatible string "atmel,sama5d2-sfr".
This gives a kernel warning 'failed to find sfr node' with non sama5d2
cpus which is removed here, thus leaving it up to having a proper DTS.

Signed-off-by: Prasanthi Chellakumar <prasanthi.chellakumar@microchip.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>