libcamera: v4l2_subdevice: Replace ImageFormats with a map

Replace the V4L2Subdevice usage of the ImageFormats class with a
std::map and the utils::map_keys() helper.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Jacopo Mondi <jacopo@jmondi.org>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/camera_sensor.h

@@ -16,13 +16,11 @@
 
 #include "libcamera/internal/formats.h"
 #include "libcamera/internal/log.h"
+#include "libcamera/internal/v4l2_subdevice.h"
 
 namespace libcamera {
 
 class MediaEntity;
-class V4L2Subdevice;
-
-struct V4L2SubdeviceFormat;
 
 struct CameraSensorInfo {
 	std::string model;
@@ -75,7 +73,7 @@ private:
 
 	std::string model_;
 
-	ImageFormats formats_;
+	V4L2Subdevice::Formats formats_;
 	Size resolution_;
 	std::vector<unsigned int> mbusCodes_;
 	std::vector<Size> sizes_;

include/libcamera/internal/v4l2_subdevice.h

@@ -32,6 +32,8 @@ struct V4L2SubdeviceFormat {
 class V4L2Subdevice : public V4L2Device
 {
 public:
+	using Formats = std::map<unsigned int, std::vector<SizeRange>>;
+
 	enum Whence {
 		ActiveFormat,
 		TryFormat,
@@ -51,7 +53,7 @@ public:
 	int setSelection(unsigned int pad, unsigned int target,
 			 Rectangle *rect);
 
-	ImageFormats formats(unsigned int pad);
+	Formats formats(unsigned int pad);
 
 	int getFormat(unsigned int pad, V4L2SubdeviceFormat *format,
 		      Whence whence = ActiveFormat);