Fix Gtkdoc warnings about missing parameters
This is very small MR to fix the following Gtkdoc warnings:
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:2162: warning: Parameter description for srt_system_info_list_egl_icds::self is missing in source code comment block.
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:2162: warning: Parameter description for srt_system_info_list_egl_icds::multiarch_tuples is missing in source code comment block.
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:2210: warning: Parameter description for srt_system_info_list_vulkan_icds::self is missing in source code comment block.
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:2210: warning: Parameter description for srt_system_info_list_vulkan_icds::multiarch_tuples is missing in source code comment block.
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:1759: warning: Parameter description for srt_system_info_set_expected_runtime_version::version (nullable) is not used from source code comment block.
/home/ryuzaki/Collabora/valve/steam-runtime-tools/steam-runtime-tools/system-info.c:1759: warning: Parameter description for srt_system_info_set_expected_runtime_version::version is missing in source code comment block.