L1 matmul API

The L1 matmul API may be summarized as:

#if defined(SREAL) || defined(SCPLX)

   void ATL_USERMM( 

const int M, const int N, const int K, const float alpha, const float *A, const int lda, const float *B, const int ldb, const float beta, float *C, const int ldc )

#elif defined(DREAL) || defined(DCPLX)

   void ATL_USERMM( 

const int M, const int N, const int K, const double alpha, const double *A, const int lda, const double *B, const int ldb, const double beta, double *C, const int ldc )

#endif