usb: renesas_usbhs: add extcon notifier to set mode for non-otg channel

usb: renesas_usbhs: add extcon notifier to set mode for non-otg channel

This patch adds extcon notifier callback to set the mode of
host/peripheral by using extcon state (e.g phy-rcar-gen3-usb2) for
non-otg channel (e.g. R-Car D3).

[Fengguang Wu: fixed sparse warning]

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
usb: renesas_usbhs: usbhs_rcar3_notifier() can be static

Fixes: 3a7cce26122e ("usb: renesas_usbhs: add extcon notifier to set mode for non-otg channel")
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>