libcamera: formats: Merge V4L2 single and multi formats

To each libcamera PixelFormat two V4L2 formats are associated, the
'single' and 'multi' format variants.

The two versions list plane contiguous and non-contiguous format
variants, and an optional argument to V4L2PixelFormat::fromPixelFormat()
was used to select which one to pick.

In order to prepare to remove V4L2PixelFormat::fromPixelFormat(), and
considering that no caller in the codebase uses the non-contiguous
format variant, merge the two formats vectors in a single one and
default the selection to the first available one, which is functionally
equivalent to what is currently implemented.

Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Paul Elder <paul.elder@ideasonboard.com>

include/libcamera/internal/formats.h

@@ -53,10 +53,7 @@ public:
 	/* \todo Add support for non-contiguous memory planes */
 	const char *name;
 	PixelFormat format;
-	struct {
-		V4L2PixelFormat single;
-		V4L2PixelFormat multi;
-	} v4l2Formats;
+	std::vector<V4L2PixelFormat> v4l2Formats;
 	unsigned int bitsPerPixel;
 	enum ColourEncoding colourEncoding;
 	bool packed;

include/libcamera/internal/v4l2_pixelformat.h

@@ -44,8 +44,7 @@ public:
 	const char *description() const;
 
 	PixelFormat toPixelFormat() const;
-	static V4L2PixelFormat fromPixelFormat(const PixelFormat &pixelFormat,
-					       bool multiplanar = false);
+	static V4L2PixelFormat fromPixelFormat(const PixelFormat &pixelFormat);
 
 private:
 	uint32_t fourcc_;