Replace --mainboard with -p internal:mainboard

NOTE:
The --list-supported-wiki output changed to use -p internal:mainboard=
instead of -m
The --list-supported output changed the heading of the mainboard list
from

Vendor Board   Status  Required option
to
Vendor Board   Status  Required value for
                       -p internal:mainboard=

Fix lb_vendor_dev_from_string() not to write to the supplied string.

Corresponding to flashrom svn r1483.

Signed-off-by: Carl-Daniel Hailfinger <c-d.hailfinger.devel.2006@gmx.net>
Acked-by: Stefan Tauner <stefan.tauner@alumni.tuwien.ac.at>
diff --git a/internal.c b/internal.c
index 386b842..5716e64 100644
--- a/internal.c
+++ b/internal.c
@@ -213,6 +213,16 @@
 	}
 	free(arg);
 
+	arg = extract_programmer_param("mainboard");
+	if (arg && strlen(arg)) {
+		lb_vendor_dev_from_string(arg);
+	} else if (arg && !strlen(arg)) {
+		msg_perr("Missing argument for mainboard.\n");
+		free(arg);
+		return 1;
+	}
+	free(arg);
+
 	get_io_perms();
 	if (register_shutdown(internal_shutdown, NULL))
 		return 1;