Make LDPC generator output directory prefix configurable

...der/nrLDPC_tools/generator_bnProc/bnProcPc_gen_BG1_avx2.c

...der/nrLDPC_tools/generator_bnProc/bnProcPc_gen_BG2_avx2.c

...coder/nrLDPC_tools/generator_bnProc/bnProc_gen_BG1_avx2.c

...coder/nrLDPC_tools/generator_bnProc/bnProc_gen_BG2_avx2.c

...ODING/nrLDPC_decoder/nrLDPC_tools/generator_bnProc/main.c

...C_tools/generator_bnProc_avx512/bnProcPc_gen_BG1_avx512.c

...C_tools/generator_bnProc_avx512/bnProcPc_gen_BG2_avx512.c

...DPC_tools/generator_bnProc_avx512/bnProc_gen_BG1_avx512.c

...DPC_tools/generator_bnProc_avx512/bnProc_gen_BG2_avx512.c

...rLDPC_decoder/nrLDPC_tools/generator_bnProc_avx512/main.c

...coder/nrLDPC_tools/generator_cnProc/cnProc_gen_BG1_avx2.c

...coder/nrLDPC_tools/generator_cnProc/cnProc_gen_BG2_avx2.c

...ODING/nrLDPC_decoder/nrLDPC_tools/generator_cnProc/main.c

...DPC_tools/generator_cnProc_avx512/cnProc_gen_BG1_avx512.c

...DPC_tools/generator_cnProc_avx512/cnProc_gen_BG2_avx512.c

...rLDPC_decoder/nrLDPC_tools/generator_cnProc_avx512/main.c

...CODING/nrLDPC_decoder/nrLDPC_tools/run_ldpc_generators.sh