[console] Fix unreachable characters in "mt" keymap

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/hci/keymap/keymap_mt.c

@@ -22,7 +22,6 @@ static struct keymap_key mt_basic[] = {
 
 /** "mt" AltGr remapping */
 static struct keymap_key mt_altgr[] = {
-	{ 0x2d, 0x5c },	/* '-' => '\\' */
 	{ 0, 0 }
 };
 

src/util/genkeymap.py

@@ -182,6 +182,11 @@ class KeyLayout(UserDict[KeyModifiers, Sequence[Key]]):
             KeyModifiers.ALTGR: [(0x28, ord('\'')), (0x2b, ord('`')),
                                  (0x35, ord('/'))],
         },
+        'mt': {
+            # Redefine erroneous key 86 as generating "\\|"
+            KeyModifiers.NONE: [(KEY_NON_US, ord('\\'))],
+            KeyModifiers.SHIFT: [(KEY_NON_US, ord('|'))],
+        },
     }
     """Fixups for erroneous keymappings produced by 'loadkeys -b'"""