utils: ipc: Include instead of forward-declare CameraSensorInfo

For structs defined in core.mojom that have the skipHeader tag, if
they're only used in function parameters (in a mojom file) then a
forward-declaration is sufficient. However, if the struct is used in
another struct in a mojom file, then the forward-declaration is
insufficient, and the definition needs to be included. Do so for
CameraSensorInfo, which is the only forward-declared struct in
ipa_interface.h, and update the documentation comment.

Signed-off-by: Paul Elder <paul.elder@ideasonboard.com>
Tested-by: Umang Jain <umang.jain@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

include/libcamera/ipa/core.mojom

@@ -38,8 +38,7 @@
  *     implemented in ipa_data_serializer.h, as it cannot be defined in mojom
  * - [skipHeader] and [skipSerdes] only work here in core.mojom.
  * - If a struct definition has [skipHeader], then the header where the
- *   struct is defined must be #included (or the struct forward-declared) in
- *   ipa_interface.h
+ *   struct is defined must be #included in ipa_interface.h
  * - If a field in a struct has a FileDescriptor, but is not explicitly
  *   defined so in mojom, then the field must be marked with the [hasFd]
  *   attribute.

include/libcamera/ipa/ipa_interface.h

@@ -18,15 +18,15 @@
 #include <libcamera/geometry.h>
 #include <libcamera/signal.h>
 
+#include "libcamera/internal/camera_sensor.h"
+
 namespace libcamera {
 
 /*
  * Structs that are defined in core.mojom and have the skipHeader tag must be
- * forward-declared or #included here.
+ * #included here.
  */
 
-struct CameraSensorInfo;
-
 class IPAInterface
 {
 public: