pci: intel: Add Intel FPGA PCIe controller driver

Add PCIe driver for Intel FPGA PCIe IP. This driver operates the PCIe IP in
rootport mode only, the EP mode is not supported. The driver is tested
with the Intel e1000e NIC driver.

Signed-off-by: Ley Foon Tan <ley.foon.tan@intel.com>
diff --git a/drivers/pci/Makefile b/drivers/pci/Makefile
index 72c09f4a..4923641 100644
--- a/drivers/pci/Makefile
+++ b/drivers/pci/Makefile
@@ -33,3 +33,4 @@
 obj-$(CONFIG_PCIE_LAYERSCAPE) += pcie_layerscape.o
 obj-$(CONFIG_PCIE_LAYERSCAPE) += pcie_layerscape_fixup.o
 obj-$(CONFIG_PCI_XILINX) += pcie_xilinx.o
+obj-$(CONFIG_PCIE_INTEL_FPGA) += pcie_intel_fpga.o