Handle "keyboardtype" prefs item from Basilisk II

SheepShaver/src/prefs_items.cpp

@@ -54,6 +54,7 @@ prefs_desc common_prefs_items[] = {
 	{"noclipconversion", TYPE_BOOLEAN, false, "don't convert clipboard contents"},
 	{"ignoresegv", TYPE_BOOLEAN, false, "ignore illegal memory accesses"},
 	{"jit", TYPE_BOOLEAN, false,        "enable JIT compiler"},
+	{"keyboardtype", TYPE_INT32, false, "hardware keyboard type"},
 	{NULL, TYPE_END, false, NULL} // End of list
 };
 
@@ -82,4 +83,6 @@ void AddPrefsDefaults(void)
 #else
 	PrefsAddBool("jit", false);
 #endif
+
+    PrefsAddInt32("keyboardtype", 5);
 }