Changed visc runtime to always use AVX as opencl target device

llvm/include/llvm/SupportVISC/DFG2LLVM.h

llvm/projects/visc-rt/visc-rt.cpp

llvm/test/VISC/parboil/.ycm_extra_conf.py

...test/VISC/parboil/benchmarks/spmv/src/opencl_cpu/Makefile

llvm/test/VISC/parboil/benchmarks/spmv/src/opencl_cpu/main.c

...est/VISC/parboil/benchmarks/spmv/src/opencl_nvidia/main.c

llvm/test/VISC/parboil/benchmarks/spmv/src/visc/main.c

llvm/test/VISC/parboil/common/Makefile.conf

llvm/test/VISC/parboil/common/include/visc.h

llvm/test/VISC/parboil/common/src/parboil_opencl.c