The Marvell PCIe host controller driver is heavily tied to Device Tree
APIs, and can only be used on platforms where the Device Tree is
used.  Therefore, it should "depends on OF" to avoid build failures on
!OF configurations.
Reported-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Tested-by: NEzequiel Garcia <ezequiel.garcia@free-electrons.com>
Signed-off-by: NThomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>