pci: mediatek: add PCIe controller support for MT7623

This adds PCIe controller support for MT7623.
This is adapted from the Linux version.

Tested-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Ryder Lee <ryder.lee@mediatek.com>
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index bdfc0c1..19e7b50 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -151,4 +151,12 @@
 	help
 	  Say Y here if you want to enable PCI controller support on AM654 SoC.
 
+config PCIE_MEDIATEK
+	bool "MediaTek PCIe Gen2 controller"
+	depends on DM_PCI
+	depends on ARCH_MEDIATEK
+	help
+	  Say Y here if you want to enable Gen2 PCIe controller,
+	  which could be found on MT7623 SoC family.
+
 endif