* remove prior_box mkldnn hard code

* add header file

* simplify PD_VISIT_TYPE

* decouple dependency between prior_box and density_prior_box

* fix pragma omp parallel error

* bypass #pragma omp_parallel_for error

* polish code

* remove visit_type headerfile

* polish codestyle

* polish codestyle

* try fix CI error

* add testcase, datatype=float64

* reset test_prior_box testcase

* add datacheck to DenseTensor

* update template name

* call prior_box with macro expand