modem-helpers: new helper to count number of bits set in a bitmask

src/mm-modem-helpers.c

@@ -1441,3 +1441,13 @@ done:
 
     return array;
 }
+
+guint
+mm_count_bits_set (gulong number)
+{
+    guint c;
+
+    for (c = 0; number; c++)
+        number &= number - 1;
+    return c;
+}

src/mm-modem-helpers.h

@@ -92,4 +92,6 @@ gint        cind_response_get_max       (CindResponse *r);
 
 GByteArray *mm_parse_cind_query_response(const char *reply, GError **error);
 
+guint mm_count_bits_set (gulong number);
+
 #endif  /* MM_MODEM_HELPERS_H */