usb: host: xhci-rcar: Avoid long wait in xhci_reset()

commit f879fc32 upstream.

The firmware of R-Car USB 3.0 host controller will control the reset.
So, if the xhci driver doesn't do firmware downloading (e.g. kernel
configuration is CONFIG_USB_XHCI_PLATFORM=y and CONFIG_USB_XHCI_RCAR
is not set), the reset of USB 3.0 host controller doesn't work
correctly. Then, the host controller will cause long wait in
xhci_reset() because the CMD_RESET bit of op_regs->command is not
cleared for 10 seconds.

So, this patch modifies the Kconfig to enable both CONFIG_USB_XHCI_PLATFORM
and CONFIG_USB_XHCI_RCAR.

Fixes: 4ac8918f (usb: host: xhci-plat: add support for the R-Car H2 and M2 xHCI controllers)
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Reviewed-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ kamal: backport to 4.2-stable: s/ARCH_RENESAS/ARCH_SHMOBILE/ ]
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/usb/host/Kconfig

@@ -33,6 +33,7 @@ config USB_XHCI_PCI
 
 config USB_XHCI_PLATFORM
 	tristate
+	select USB_XHCI_RCAR if ARCH_SHMOBILE
 
 config USB_XHCI_MVEBU
 	tristate "xHCI support for Marvell Armada 375/38x"
@@ -44,7 +45,7 @@ config USB_XHCI_MVEBU
 
 config USB_XHCI_RCAR
 	tristate "xHCI support for Renesas R-Car SoCs"
-	select USB_XHCI_PLATFORM
+	depends on USB_XHCI_PLATFORM
 	depends on ARCH_SHMOBILE || COMPILE_TEST
 	---help---
 	  Say 'Y' to enable the support for the xHCI host controller