introduce support for new ngff_cardem board

This adds support for the new ngff_cardem board, a board that
basically combines a ngff breakout board with a built-in SIMtrace2.

Cardem works, but depending on the modem it might need a adjusted ATR to
ensure a lower baud  rate is used by the modem, high rates might lead
to weird power cycling of the card after a few transfers.

Trace was also tested and appears to work as expected.

Change-Id: Ia96124fbe8a752c98e7fd4096d542a3b2b9bc255

firmware/libboard/ngff_cardem/include/wwan_led.h

@@ -0,0 +1,20 @@
+/* Code to read/track the status of the WWAN LEDs of attached modems
+ * 
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307, USA
+ */
+#pragma once
+
+int wwan_led_active(int wwan);
+int wwan_led_init(void);