fix(rtl): remove default number of BPM in register

rdl/corr_matrix.rdl

@@ -155,7 +155,7 @@ addrmap corr_matrix {
     reg {
         desc="Number of ID to count for matrix multiplication.";
         desyrdl_data_type="uint16";
-        field {sw = rw; hw = r;} data[16] = `C_N_MM_BPM;
+        field {sw = rw; hw = r;} data[16];
     } MM_ID_CNT;
 
     reg {