USB: host: ohci-at91: merge loops in ohci_hcd_at91_drv_probe

ohci_hcd_at91_drv_probe() has four at91_for_each_port. They can be merged
into two loops without changing the driver behaviour.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>