usb: Specify dependencies on USB_XHCI_PLATFORM with 'depends on'

Some USB controller drivers that depend on the xhci-plat driver
specify this dependency using 'select' in Kconfig. This is not
recommended for symbols that have other dependencies as it may
lead to invalid configurations. Use 'depends on' to specify the
dependency instead of 'select'.

For DWC3 move the dependency from USB_DWC3 to USB_DWC3_HOST and
USB_DWC3_DUAL_ROLE, to make the DWC3 core selectable for
gadget-only mode when USB_XHCI_PLATFORM=n.

Signed-off-by: Matthias Kaehlcke <mka@chromium.org>

drivers/usb/cdns3/Kconfig

@@ -1,7 +1,7 @@
 config USB_CDNS_SUPPORT
 	tristate "Cadence USB Support"
 	depends on USB_SUPPORT && (USB || USB_GADGET) && HAS_DMA
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
+	depends on !USB_XHCI_HCD || USB_XHCI_PLATFORM
 	select USB_ROLE_SWITCH
 	help
 	  Say Y here if your system has a Cadence USBSS or USBSSP

drivers/usb/dwc3/Kconfig

@@ -3,7 +3,6 @@
 config USB_DWC3
 	tristate "DesignWare USB3 DRD Core Support"
 	depends on (USB || USB_GADGET) && HAS_DMA
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
 	select USB_ROLE_SWITCH if USB_DWC3_DUAL_ROLE
 	help
 	  Say Y or M here if your system has a Dual Role SuperSpeed
@@ -30,6 +29,7 @@ choice
 config USB_DWC3_HOST
 	bool "Host only mode"
 	depends on USB=y || USB=USB_DWC3
+	depends on USB_XHCI_PLATFORM
 	help
 	  Select this when you want to use DWC3 in host mode only,
 	  thereby the gadget feature will be regressed.
@@ -44,6 +44,7 @@ config USB_DWC3_GADGET
 config USB_DWC3_DUAL_ROLE
 	bool "Dual Role mode"
 	depends on ((USB=y || USB=USB_DWC3) && (USB_GADGET=y || USB_GADGET=USB_DWC3))
+	depends on USB_XHCI_PLATFORM
 	depends on (EXTCON=y || EXTCON=USB_DWC3)
 	help
 	  This is the default mode of working of DWC3 controller where

drivers/usb/host/Kconfig

@@ -80,7 +80,7 @@ config USB_XHCI_MTK
 
 config USB_XHCI_MVEBU
 	tristate "xHCI support for Marvell Armada 375/38x/37xx"
-	select USB_XHCI_PLATFORM
+	depends on USB_XHCI_PLATFORM
 	depends on HAS_IOMEM
 	depends on ARCH_MVEBU || COMPILE_TEST
 	help
@@ -112,9 +112,9 @@ config USB_EHCI_BRCMSTB
 config USB_BRCMSTB
 	tristate "Broadcom STB USB support"
 	depends on (ARCH_BRCMSTB && PHY_BRCM_USB) || COMPILE_TEST
+	depends on !USB_XHCI_HCD || USB_XHCI_PLATFORM
 	select USB_OHCI_HCD_PLATFORM if USB_OHCI_HCD
 	select USB_EHCI_BRCMSTB if USB_EHCI_HCD
-	select USB_XHCI_PLATFORM if USB_XHCI_HCD
 	help
 	  Enables support for XHCI, EHCI and OHCI host controllers
 	  found in Broadcom STB SoC's.