add preset to compile with hcc

# preset that will enable hcc plus gcc with support for MPI and OpenMP (on Linux boxes)

set(CMAKE_CXX_COMPILER "hcc" CACHE STRING "" FORCE)

set(CMAKE_C_COMPILER "gcc" CACHE STRING "" FORCE)

set(CMAKE_CXX_FLAGS "-Wall -Wextra -g -O2 -DNDEBG" CACHE STRING "" FORCE)

set(MPI_CXX "hcc" CACHE STRING "" FORCE)

set(MPI_CXX_COMPILER "mpicxx" CACHE STRING "" FORCE)

unset(HAVE_OMP_H_INCLUDE CACHE)

set(OpenMP_CXX "hcc" CACHE STRING "" FORCE)

set(OpenMP_CXX_FLAGS "-fopenmp" CACHE STRING "" FORCE)

set(OpenMP_CXX_LIB_NAMES "omp" CACHE STRING "" FORCE)

set(OpenMP_omp_LIBRARY "libomp.so" CACHE PATH "" FORCE)