ASoC: eukrea-tlv320: add support for our i.MX25 board

* tdm slot has to be configured to get sound working on i.MX25

Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>