PCI: pciehp: Enable by default if USB4 enabled

Thunderbolt/USB4 PCIe tunneling depends on native PCIe hotplug.  Enable
pciehp by default if USB4 is enabled.

[bhelgaas: squash, update subject, commit logs, tidy whitespace]
Link: https://lore.kernel.org/r/20221115113857.35800-2-albert.zhou.50@gmail.com
Link: https://lore.kernel.org/r/20221115113857.35800-3-albert.zhou.50@gmail.com
Signed-off-by: Albert Zhou <albert.zhou.50@gmail.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

drivers/pci/hotplug/Kconfig

@@ -6,11 +6,14 @@
 menuconfig HOTPLUG_PCI
 	bool "Support for PCI Hotplug"
 	depends on PCI && SYSFS
+	default y if USB4
 	help
 	  Say Y here if you have a motherboard with a PCI Hotplug controller.
 	  This allows you to add and remove PCI cards while the machine is
 	  powered up and running.
 
+	  Thunderbolt/USB4 PCIe tunneling depends on native PCIe hotplug.
+
 	  When in doubt, say N.
 
 if HOTPLUG_PCI

drivers/pci/pcie/Kconfig

@@ -4,6 +4,7 @@
 #
 config PCIEPORTBUS
 	bool "PCI Express Port Bus support"
+	default y if USB4
 	help
 	  This enables PCI Express Port Bus support. Users can then enable
 	  support for Native Hot-Plug, Advanced Error Reporting, Power
@@ -15,9 +16,12 @@ config PCIEPORTBUS
 config HOTPLUG_PCI_PCIE
 	bool "PCI Express Hotplug driver"
 	depends on HOTPLUG_PCI && PCIEPORTBUS
+	default y if USB4
 	help
-	  Say Y here if you have a motherboard that supports PCI Express Native
-	  Hotplug
+	  Say Y here if you have a motherboard that supports PCIe native
+	  hotplug.
+
+	  Thunderbolt/USB4 PCIe tunneling depends on native PCIe hotplug.
 
 	  When in doubt, say N.