media: v4l2-core: move spi helpers out of v4l2-common.c

Separate the spi helpers to v4l2-spi.c, in order to get rid
of the ifdefery. No functional changes intended, this is
just a cosmetic change to organize the code better.

Signed-off-by: Ezequiel Garcia <ezequiel@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>

include/media/v4l2-common.h

@@ -216,11 +216,10 @@ const unsigned short *v4l2_i2c_tuner_addrs(enum v4l2_i2c_tuner_type type);
 /* ------------------------------------------------------------------------- */
 
 /* SPI Helper functions */
-#if defined(CONFIG_SPI)
 
 #include <linux/spi/spi.h>
 
-struct spi_device;
+#if defined(CONFIG_SPI)
 
 /**
  *  v4l2_spi_new_subdev - Load an spi module and return an initialized
@@ -246,6 +245,21 @@ struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
  */
 void v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
 		const struct v4l2_subdev_ops *ops);
+
+#else
+
+static inline struct v4l2_subdev *
+v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
+		    struct spi_master *master, struct spi_board_info *info)
+{
+	return NULL;
+}
+
+static inline void
+v4l2_spi_subdev_init(struct v4l2_subdev *sd, struct spi_device *spi,
+		     const struct v4l2_subdev_ops *ops)
+{}
+
 #endif
 
 /* ------------------------------------------------------------------------- */