PCI: imx6: Probe the PCIe in fs_initcall()

PCI: imx6: Probe the PCIe in fs_initcall()

Probe the PCIe driver in fs_initcall() instead of module_init()
to assure that pci_assign_unassigned_resources() will be called
early.  This function is called in dw_pcie_host_init(), which is
in turn called from imx6_add_pcie_port(), which is called from
imx6_pcie_probe().  If this is not called early, we will hit
resource collisions since pcieport driver is then probed way too
late.

Signed-off-by: Marek Vasut <marex@denx.de>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Cc: Frank Li <lznuaa@gmail.com>
Cc: Jingoo Han <jg1.han@samsung.com>
Cc: Mohit KUMAR <Mohit.KUMAR@st.com>
Cc: Pratyush Anand <pratyush.anand@st.com>
Cc: Richard Zhu <r65037@freescale.com>
Cc: Sascha Hauer <s.hauer@pengutronix.de>
Cc: Sean Cross <xobs@kosagi.com>
Cc: Siva Reddy Kallam <siva.kallam@samsung.com>
Cc: Srikanth T Shivanand <ts.srikanth@samsung.com>
Cc: Tim Harvey <tharvey@gateworks.com>
Cc: Troy Kisky <troy.kisky@boundarydevices.com>
Cc: Yinghai Lu <yinghai@kernel.org>