emulators/rpcs3: unbreak with LLD by default

/usr/bin/ld: error: cannot preempt symbol: alcOpenDevice

defined in /usr/local/lib/libopenal.so
referenced by OpenALThread.cpp

OpenALThread.cpp.o:(OpenALThread::OpenALThread()) in archive rpcs3/Emu/librpcs3_emu.a

/usr/bin/ld: error: cannot preempt symbol: alcGetError

defined in /usr/local/lib/libopenal.so
referenced by OpenALThread.cpp

OpenALThread.cpp.o:(OpenALThread::OpenALThread()) in archive rpcs3/Emu/librpcs3_emu.a

Reported by: pkg-fallout