ARM: shmobile: koelsch: enable HS-USB

Enable HS-USB device for the Koelsch board, defining the GPIO that the driver
should check when probing (which is the ID output from MAX3355 OTG chip).

Note that there will be pinctrl-related error messages if both internal PCI
and HS-USB drivers are enabled but they should be just ignored.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
[Sergei: added pin function/group and prop, moved device node, fixed summary,
added changelog]
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>