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/camera.cpp

@@ -937,7 +937,7 @@ const std::set<Stream *> &Camera::streams() const
  * \return A CameraConfiguration if the requested roles can be satisfied, or a
  * null pointer otherwise.
  */
-std::unique_ptr<CameraConfiguration> Camera::generateConfiguration(const StreamRoles &roles)
+std::unique_ptr<CameraConfiguration> Camera::generateConfiguration(Span<const StreamRole> roles)
 {
 	Private *const d = _d();
 
@@ -970,6 +970,12 @@ std::unique_ptr<CameraConfiguration> Camera::generateConfiguration(const StreamR
 	return config;
 }
 
+/**
+ * \fn std::unique_ptr<CameraConfiguration> \
+ *     Camera::generateConfiguration(std::initializer_list<StreamRole> roles)
+ * \overload
+ */
+
 /**
  * \brief Configure the camera prior to capture
  * \param[in] config The camera configurations to setup