[ARM] Orion: move setting up PCIe WA window into PCIe setup path

It makes no sense to do PCIe WA window setup in the individual
board support files while the decision whether or not to use the
PCIe WA access method is made in a different place, in the PCIe
support code.

This patch moves the configuration of a PCIe WA window from the
individual Orion board support files to the central Orion PCIe
support code.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Russell King <linux@arm.linux.org.uk>