media: tuner-types: add kernel-doc markups for struct tunertype

This struct is lacking documentation. Add it.
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

include/media/tuner-types.h

@@ -171,6 +171,21 @@ struct tuner_params {
 	struct tuner_range *ranges;
 };
 
+/**
+ * struct tunertype - describes the known tuners.
+ *
+ * @name:	string with the tuner's name.
+ * @count:	size of &struct tuner_params array.
+ * @params:	pointer to &struct tuner_params array.
+ *
+ * @min:	minimal tuner frequency, in 62.5 kHz step.
+ *		should be multiplied to 16 to convert to MHz.
+ * @max:	minimal tuner frequency, in 62.5 kHz step.
+ *		Should be multiplied to 16 to convert to MHz.
+ * @stepsize:	frequency step, in Hz.
+ * @initdata:	optional byte sequence to initialize the tuner.
+ * @sleepdata:	optional byte sequence to power down the tuner.
+ */
 struct tunertype {
 	char *name;
 	unsigned int count;