plugins: add userdata for qemu_plugin_{uninstall, reset}
We do both at the same time because they internally use the same
implementation.
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Link: https://lore.kernel.org/qemu-devel/20260615193526.2883349-3-pierrick.bouvier@oss.qualcomm.com
Signed-off-by: Pierrick Bouvier <pierrick.bouvier@oss.qualcomm.com>