Add thread_warp_size for Metal device in default target attributes (#8202)
Add thread_warp_size for Metal device in default target attributes (#8202)


Laurawly/tvm-1,dmlc/tvm,Laurawly/tvm-1,Laurawly/tvm-1,Laurawly/tvm-1,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,Laurawly/tvm-1,dmlc/tvm,Laurawly/tvm-1,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,dmlc/tvm,Laurawly/tvm-1,dmlc/tvm,dmlc/tvm,Laurawly/tvm-1