usb: common: usb-conn-gpio: Set last role to unknown before initial detection

Currently if we bootup a device without cable connected, then
usb-conn-gpio won't call set_role() since last_role is same as
current role. This happens because during probe last_role gets
initialised to zero.

To avoid this, added a new constant in enum usb_role, last_role
is set to USB_ROLE_UNKNOWN before performing initial detection.

While at it, also handle default case for the usb_role switch
in cdns3, intel-xhci-usb-role-switch & musb/jz4740 to avoid
build warnings.

Fixes: 4602f3bf

 ("usb: common: add USB GPIO based connection detection driver")
Signed-off-by: Prashanth K <quic_prashk@quicinc.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Message-ID: <1685544074-17337-1-git-send-email-quic_prashk@quicinc.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>