usb: dwc3-generic: Export glue structures and functions
In order to allow external SoC-dependent glue drivers to use dwc3-generic
functions, push the glue structures and export the functions to a header
file.
The SoC-dependent glue drivers can only define their own wrapper driver
and specify these functions. The drivers can also add their own compatible
strings and configure functions.
Signed-off-by: Kunihiko Hayashi <hayashi.kunihiko@socionext.com> Reviewed-by: Marek Vasut <marex@denx.de>