starfive: pci: Add StarFive JH7110 pcie driver

Add pcie driver for StarFive JH7110, Also add PLDA
PCIe controller common driver functions.

Several devices are tested:
a) M.2 NVMe SSD
b) Realtek 8169 Ethernet adapter.

Signed-off-by: Mason Huo <mason.huo@starfivetech.com>
Signed-off-by: Minda Chen <minda.chen@starfivetech.com>
Acked-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Leo Yu-Chi Liang <ycliang@andestech.com>
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 93e6f50..a0bf44d 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -393,4 +393,17 @@
 	 Say 'Y' here if you want support for Xilinx / AMD NWL PCIe
 	 controller as Root Port.
 
+config PCIE_PLDA_COMMON
+	bool
+
+config PCIE_STARFIVE_JH7110
+	bool "Enable Starfive JH7110 PCIe driver"
+	select PCIE_PLDA_COMMON
+	imply STARFIVE_JH7110
+	imply CLK_JH7110
+	imply RESET_JH7110
+	help
+	  Say Y here if you want to enable PLDA XpressRich PCIe controller
+	  support on StarFive JH7110 SoC.
+
 endif