pci: mediatek: add PCIe controller support for filogic silicon

Add MediaTek GEN3 PCIe controller support for filogic silicon.
This is adapted from the Linux version of the driver.

Signed-off-by: John Crispin <john@phrozen.org>
[ fix minor problems, fix checkpatch errors ]
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 8d02ab8..22a56f4 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -350,6 +350,13 @@
 	  Say Y here if you want to enable Gen2 PCIe controller,
 	  which could be found on MT7623 SoC family.
 
+config PCIE_MEDIATEK_GEN3
+	bool "MediaTek PCIe Gen3 controller"
+	depends on ARCH_MEDIATEK
+	help
+	  Say Y here if you want to enable Gen3 PCIe controller,
+	  which could be found on the Mediatek Filogic SoC family.
+
 config PCIE_DW_MESON
 	bool "Amlogic Meson DesignWare based PCIe controller"
 	depends on ARCH_MESON