arm: kirkwood: move PCIe window init to legacy driver

Since we are going to enable the usage of the mvebu PCIe driver on
Kirkwood, we don't want the PCIe windows to be unconditionally created
by kirkwood_setup_wins(). Therefore, we move the PCIe window
initialization into the legacy PCIe driver
(arch/arm/mach-kirkwood/pcie.c).

The platforms using the legacy driver will see their windows
statically allocated by
arch/arm/mach-kirkwood/pcie.c:kirkwood_pcie_init(). The platforms
using the new driver in drivers/pci/ will see their windows
dynamically allocated directly by the driver.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>