DIRAC ITT 2020 MI50 compilation

Similar to other systems for prerequisites.

export PATH=/opt/rocm/bin:${PATH}
../configure --enable-unified=no \
	     --enable-accelerator=hip \
	     --enable-comms=mpi3-auto \
	     --enable-simd=GPU \
	     --enable-gen-simd-width=64 \
	     CXX=hipcc \
	     MPICXX=mpicxx \
	     CPPFLAGS="-I/opt/rocm/rocthrust/include" \
	     LDFLAGS="-L/opt/rocm/rocthrust/lib"

Manually removed Gparity code due to HIP compiler internal compiler error, then it worked.