ir-rx51: add DT support to driver

With the upcoming removal of legacy boot, lets add support to one of the
last N900 drivers remaining without it. As the driver still uses omap
dmtimer, add auxdata as well.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>