* revise LSTM spec Signed-off-by: fishbell <bell.song@intel.com> * add param check and related test case Signed-off-by: fishbell <bell.song@intel.com> * fix clang-format Signed-off-by: fishbell <bell.song@intel.com> * use static_cast to replace c style force conversion Signed-off-by: fishbell <bell.song@intel.com>