PCI: tegra: Add Kconfig help text

Add a standard help text to the Kconfig entry for the Tegra PCIe host
controller driver.
Signed-off-by: NThierry Reding <treding@nvidia.com>
Signed-off-by: NBjorn Helgaas <bhelgaas@google.com>

drivers/pci/host/Kconfig

@@ -33,6 +33,9 @@ config PCI_IMX6
 config PCI_TEGRA
 	bool "NVIDIA Tegra PCIe controller"
 	depends on ARCH_TEGRA && !ARM64
+	help
+	  Say Y here if you want support for the PCIe host controller found
+	  on NVIDIA Tegra SoCs.
 
 config PCI_RCAR_GEN2
 	bool "Renesas R-Car Gen2 Internal PCI controller"