Currently the code is not built by any modules. That will
be fixed later. The Atmel ARM bus interface file part of this
commit is just for sake of example. All registers and bits are
declared like macros and not C-structures like in official
Synopsis header files. This driver mostly origins from the
musb_otg.c driver in FreeBSD except that the chip specific
programming has been replaced by the one for DWC 2.0 USB OTG.
Some parts related to system suspend and resume have been left
like empty functions for the future. USB suspend and resume is
fully supported.