sound: oxygen: allow custom MCLK rates

Add a callback that allows model drivers to modify the default I2S MCLK
rate.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/oxygen/oxygen.h b/sound/pci/oxygen/oxygen.h
index 2ac3b3c..6147216 100644
--- a/sound/pci/oxygen/oxygen.h
+++ b/sound/pci/oxygen/oxygen.h
@@ -78,6 +78,8 @@
 	void (*resume)(struct oxygen *chip);
 	void (*pcm_hardware_filter)(unsigned int channel,
 				    struct snd_pcm_hardware *hardware);
+	unsigned int (*get_i2s_mclk)(struct oxygen *chip, unsigned int channel,
+				     struct snd_pcm_hw_params *hw_params);
 	void (*set_dac_params)(struct oxygen *chip,
 			       struct snd_pcm_hw_params *params);
 	void (*set_adc_params)(struct oxygen *chip,
@@ -163,6 +165,8 @@
 /* oxygen_pcm.c */
 
 int oxygen_pcm_init(struct oxygen *chip);
+unsigned int oxygen_default_i2s_mclk(struct oxygen *chip, unsigned int channel,
+				     struct snd_pcm_hw_params *hw_params);
 
 /* oxygen_io.c */