droid 4: add special handling required for voice calls and SIM

Droid 4 modem is "special" (aka broken) so it seems to need a bit of
error handling.

drivers/atmodem/sim.c

@@ -199,6 +199,7 @@ static void at_sim_read_info(struct ofono_sim *sim, int fileid,
 	case OFONO_VENDOR_SPEEDUP:
 	case OFONO_VENDOR_QUALCOMM_MSM:
 	case OFONO_VENDOR_SIMCOM:
+	case OFONO_VENDOR_DROID:
 		/* Maximum possible length */
 		len += sprintf(buf + len, ",0,0,255");
 		break;

drivers/atmodem/vendor.h

@@ -27,6 +27,7 @@ enum ofono_vendor {
 	OFONO_VENDOR_MBM,
 	OFONO_VENDOR_GOBI,
 	OFONO_VENDOR_QUALCOMM_MSM,
+	OFONO_VENDOR_DROID,
 	OFONO_VENDOR_OPTION_HSO,
 	OFONO_VENDOR_ZTE,
 	OFONO_VENDOR_HUAWEI,

drivers/atmodem/voicecall.c

@@ -161,6 +161,11 @@ static void clcc_poll_cb(gboolean ok, GAtResult *result, gpointer user_data)
 			goto poll_again;
 		}
 
+		if (vd->vendor == OFONO_VENDOR_DROID) {
+			poll_again = TRUE;
+			goto poll_again;
+		}
+
 		ofono_error("We are polling CLCC and received an error");
 		ofono_error("All bets are off for call management");
 		return;