Orion: enable access to local config space

This patch enables access to the local PCIe/PCI configuration
space, and is necessary for such things as PCI Advanced Error
Recovery to work.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Reviewed-by: Tzachi Perelstein <tzachi@marvell.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Nicolas Pitre <nico@marvell.com>