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/programmer.h b/programmer.h
index d6b9cd6..6f69db1 100644
--- a/programmer.h
+++ b/programmer.h
@@ -264,7 +264,7 @@
 void cleanup_cpu_msr(void);
 
 /* cbtable.c */
-void lb_vendor_dev_from_string(char *boardstring);
+void lb_vendor_dev_from_string(const char *boardstring);
 int coreboot_init(void);
 extern char *lb_part, *lb_vendor;
 extern int partvendor_from_cbtable;