Enhance the error messages for  files in operators/math

Optimize the concat and split kernel for specical cases when the number of inputs/outputs is 2 (#17415)

* Optimize the concat and split kernel for special cases that the number of inputs/outputs is 2.
test=develop

* Refine codes.
test=develop

* Correct the condition.
test=develop

* Move the define of tmp_data outside the if statement.

* Print the cudnn minor version.
test=develop

* Fix the case when in_num/o_num is 1 in concat/split op.
test=develop

* Remove const_cast.
test=develop

* speedup split_op
test=develop

* speedup split_op
test=develop

* rename ConcatGrad to Split

* refine concat and split
test=develop

* fix compile error

* Fix CPPLint errors

* Fix CPPLint errors in sequence2batch

* Fix compilation

* Fix LSTM op and GRU op

* Fix LSTMP op

* Fix more cpplint errors in operators/math

* Address Code review feedback