Add batch functionnality for the potrf kernels

compute/CMakeLists.txt

compute/zgemm_batch.c

compute/zherk_batch.c

compute/zplghe_batch.c

compute/zpotrf_batch.c

compute/ztrsm_batch.c

include/chameleon/chameleon_z.h

testing/CMakeLists.txt

testing/testing_zgemm_batch.c

testing/testing_zherk_batch.c

testing/testing_zpotrf_batch.c

testing/testing_ztrsm_batch.c