The check for the mux_signal callback was wrong which prevents us to
configure the 6pin port's FSR/CLKR signal mux.
Reported-by: NCF Adad <cfadad@rocketmail.com>
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Acked-by: NJarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org (3.4+)