libcamera: camera: Take span of StreamRole instead of vector

Change the parameter type of `generateConfiguration()` from `const std::vector&`
to `libcamera::Span`. A span is almost always preferable to a const vector ref
because it does not force dynamic allocation when none are needed, and it allows
any contiguous container to be used.

A new overload is added that accepts an initializer list so that

  cam->generateConfiguration({ ... })

keeps working.

There is no API break since a span can be constructed from a vector
and the initializer list overload takes care of the initializer lists,
but this change causes an ABI break.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
[Kieran: Apply checkstyle fixups]
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

src/libcamera/pipeline/simple/simple.cpp

@@ -316,7 +316,7 @@ public:
 	SimplePipelineHandler(CameraManager *manager);
 
 	std::unique_ptr<CameraConfiguration> generateConfiguration(Camera *camera,
-		const StreamRoles &roles) override;
+								   Span<const StreamRole> roles) override;
 	int configure(Camera *camera, CameraConfiguration *config) override;
 
 	int exportFrameBuffers(Camera *camera, Stream *stream,
@@ -1044,7 +1044,7 @@ SimplePipelineHandler::SimplePipelineHandler(CameraManager *manager)
 }
 
 std::unique_ptr<CameraConfiguration>
-SimplePipelineHandler::generateConfiguration(Camera *camera, const StreamRoles &roles)
+SimplePipelineHandler::generateConfiguration(Camera *camera, Span<const StreamRole> roles)
 {
 	SimpleCameraData *data = cameraData(camera);
 	std::unique_ptr<CameraConfiguration> config =