This supports USB2 PHY channel #0 on ULCB Kingfisher board

The dedicated USB0_PWEN pin is used to control CN13 VBUS source from U43
power supply.
MAX3355 can also provide VBUS, hence it should be disabled via OTG_OFFVBUSn
node coming from gpio expander TCA9539.
Set MAX3355 enabled using OTG_EXTLPn node to be able to read OTG ID of
CN13.
Signed-off-by: Vladimir Barinov <vladimir.barinov@cogentembedded.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>