[media] media: rc: Introduce RX51 IR transmitter driver

This is the driver for the IR transmitter diode found on the Nokia
N900 (also known as RX51) device. The driver is mostly the same as
found in the original 2.6.28 based kernel that comes with the device.

The following modifications have been made compared to the original
driver version:

- Adopt to the changes that has happen in the kernel during the past
  five years, such as the change in the include paths

- The OMAP DM-timers require much more care nowadays. The timers need
  to be enabled and disabled or otherwise many actions fail. Timers
  must not be freed without first stopping them or otherwise the timer
  cannot be requested again.

The code has been tested with sending IR codes with N900 device
running Debian userland. The device receiving the codes was Anysee
DVB-C USB receiver.

Signed-off-by: Timo Kokkonen <timo.t.kokkonen@iki.fi>
Cc: Tony Lindgren <tony@atomide.com>
Cc: linux-omap@vger.kernel.org
Cc: Sakari Ailus <sakari.ailus@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>