usb: ohci-at91: Forcibly suspend ports while USB suspend

The usb controller does not manage correctly the suspend mode for
the ehci. In echi mode, there is no way to suspend without any
device connected to it. This is why this specific control is added
to fix this issue. Since the suspend mode works in ohci mode, this
specific control works by suspend the usb controller in ohci mode.

This specific control is by setting the SUSPEND_A/B/C fields of
SFR_OHCIICR(OHCI Interrupt Configuration Register) in the SFR
while the OHCI USB suspend.

This set operation must be done before the USB clock disabled,
clear operation after the USB clock enabled.

Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>