games/openclonk: Update to 8.0

Additional port changes:

• Changed to DISTVERSION
• Moved BROKEN_powerpc64 to a proper place
• Updated LIB_DEPENDS,USES,USE_GL,USE_SDL
• Choosing OpenAL through CMAKE_ARGS
• Added 3 patches

PR: 226111
Submitted by: Kevin Zheng <kevinz5000@gmail.com> (maintainer)
Approved by: tcberner (mentor, implicit)