Modified makefiles to add _platform to the build dir

llvm/test/VISC/MatrixMultiplication/visc_gemm.ll

llvm/test/VISC/MatrixMultiplication/visc_gemm_2_level.ll

.../test/VISC/MatrixMultiplication/visc_gemm_2_level_host.ll

...st/VISC/MatrixMultiplication/visc_gemm_2_level_outedge.ll

...test/VISC/MatrixMultiplication/visc_gemm_2_level_param.ll

llvm/test/VISC/MatrixMultiplication/visc_gemm_ptx.ll

llvm/test/VISC/parboil/benchmarks/lbm/Makefile

...test/VISC/parboil/benchmarks/lbm/src/opencl_nvidia/main.c

llvm/test/VISC/parboil/benchmarks/sgemm/Makefile

...est/VISC/parboil/benchmarks/sgemm/src/opencl_base/main.cc

llvm/test/VISC/parboil/benchmarks/spmv/Makefile

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

llvm/test/VISC/parboil/benchmarks/stencil/Makefile

...st/VISC/parboil/benchmarks/stencil/src/opencl_base/main.c

llvm/test/VISC/parboil/common/mk/opencl.mk

llvm/test/VISC/parboil/common/mk/visc.mk