Remove implicit dependency on private Numpy API

Resolves bug where building mkl_umath with Numpy v1.20 would result in the
following error:
  - numpy/__multiarray_api.h(19): error: identifier "PyArray_DTypeMeta" is
    undefined

Author: AndresGuzman-Ballen

mkl_umath/src/loops_intel.c.src

@@ -5,8 +5,6 @@
 #include "mathimf.h"
 #include "Python.h"
 
-#define _UMATHMODULE
-#define _MULTIARRAYMODULE
 #define NPY_NO_DEPRECATED_API NPY_API_VERSION
 
 #include "numpy/npy_common.h"