USB: Au1xxx-usb: clean up ohci/ehci bus glue sources.

- Fold multiple probe/remove callbacks into one function;
- minor style fixes, no functional changes.

Tested on Au1200.

Signed-off-by: Manuel Lauss <mano@roarinelk.homelinux.net>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>