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/py/libcamera/py_main.cpp

@@ -208,7 +208,10 @@ PYBIND11_MODULE(_libcamera, m)
 		})
 
 		/* Keep the camera alive, as StreamConfiguration contains a Stream* */
-		.def("generate_configuration", &Camera::generateConfiguration, py::keep_alive<0, 1>())
+		.def("generate_configuration", [](Camera &self, const std::vector<StreamRole> &roles) {
+			return self.generateConfiguration(roles);
+		}, py::keep_alive<0, 1>())
+
 		.def("configure", [](Camera &self, CameraConfiguration *config) {
 			int ret = self.configure(config);
 			if (ret)