usb: omap: avoid mach/*.h headers

The omap usb drivers still rely on mach/*.h headers that
are explicitly or implicitly included, but all the required
definitions are now in include/linux/soc/ti/, so use those
instead and allow compile-testing on other architectures.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>