usb: langwell_udc: add HighSpeed/FullSpeed events notification

usb: langwell_udc: add HighSpeed/FullSpeed events notification

It adds notification to Intel Penwell otg transceiver driver for
HighSpeed/FullSpeed. This change mainly to support battery charging
current negotiation for Charging Downstream Port(CDP) case. USB OTG
Transceiver driver will notify battery driver about charging current
limitation change according to different Speed Mode (HS/FS).

Change-Id: Icc7f8004b8173cd74ae78d5fce90d3c57e94a847
Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Dirk Brandewie <dirk.brandewie@gmail.com>