powerpc/83xx: Add USB Host/Gadget support for MPC8360E-MDS boards

- Update the device tree per QE USB bindings;
- Add timer (FSL GTM) node;
- Add gpio-controller node for BCSR13 bank (GPIOs on that bank
  are used to control the USB transceiver);
- Set up other BCSR registers;
- Configure the QE Par IO.

The work is loosely based on Li Yang's patch[1], which was used
to support peripheral mode only.

[1] http://ozlabs.org/pipermail/linuxppc-dev/2008-August/061357.html

The s-o-b line of the original patch preserved here.

Signed-off-by: Li Yang <leoli@freescale.com>
Signed-off-by: Anton Vorontsov <avorontsov@ru.mvista.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>