usb: move ci13xxx and related code to drivers/usb/chipidea

Since chipidea is a dual role controller, it makes sense to move it
to its own directory, where we can also have host, otg and platform
code related to this controller. It also makes sense to break out
the driver into several compilation units like udc, host, debugging
code, etc.

Firstly, let's move the udc and platform code to drivers/usb/chipidea.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>