fuze+: add RDS support
I successfully identified the STC/RDS pin as B2P27.
Strangely the OF uses polling instead of interrupts
but since they routed it, let's use it! On the fuze+
the fmradio i2c uses bit toggling so we can't read
the RDS data in the interrupt context. Instead we
defer the work to a thread.
Change-Id: Iedfa425320e6c91b4351b72e97c732696bdb2b73
Reviewed-on: http://gerrit.rockbox.org/236
Reviewed-by: Bertrik Sikken <bertrik@sikken.nl>
Reviewed-by: Amaury Pouly <amaury.pouly@gmail.com>