The device tree property uses '-' not '_'.
Signed-off-by: Dylan Reid <dgreid@chromium.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
                                          source.
 - simple-audio-card,mclk-fs             : Multiplication factor between stream rate and codec
                                          mclk.
-- simple-audio-card,hp_det_gpio                : Reference to GPIO that signals when
+- simple-audio-card,hp-det-gpio                : Reference to GPIO that signals when
                                          headphones are attached.
-- simple-audio-card,mic_det_gpio       : Reference to GPIO that signals when
+- simple-audio-card,mic-det-gpio       : Reference to GPIO that signals when
                                          a microphone is attached.
 
 Optional subnodes: