header files: clean up

1. format;
2. Slow RTC memory reverse 2KB;

components/esp32/include/rom/bigint.h

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+
 #ifndef _ROM_BIGINT_H_
 #define _ROM_BIGINT_H_