DOC: fixed register_extension_dtype import statement (#50770)

Author: lpizzinidev

pandas/core/arrays/floating.py

@@ -2,8 +2,8 @@
 
 import numpy as np
 
+from pandas.core.dtypes.base import register_extension_dtype
 from pandas.core.dtypes.common import is_float_dtype
-from pandas.core.dtypes.dtypes import register_extension_dtype
 
 from pandas.core.arrays.numeric import (
     NumericArray,