PCI/ASPM: Remove dependency on PCIEPORTBUS

The ASPM support does not depend on the portdrv, so remove the Kconfig
dependency.

Link: https://lore.kernel.org/r/20191106222420.10216-4-helgaas@kernel.org
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Andrew Murray <andrew.murray@arm.com>
diff --git a/drivers/pci/pcie/Kconfig b/drivers/pci/pcie/Kconfig
index b0d781d..b196ad8 100644
--- a/drivers/pci/pcie/Kconfig
+++ b/drivers/pci/pcie/Kconfig
@@ -63,7 +63,7 @@
 #
 config PCIEASPM
 	bool "PCI Express ASPM control" if EXPERT
-	depends on PCI && PCIEPORTBUS
+	depends on PCI
 	default y
 	help
 	  This enables OS control over PCI Express ASPM (Active State