Input: i8042 - disable MUX mode for Sharp MM20

Add yet another entry to the ever-growing list of boxes with
non-working MUX implementation.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/serio/i8042-x86ia64io.h b/drivers/input/serio/i8042-x86ia64io.h
index 273bb3b..057beca 100644
--- a/drivers/input/serio/i8042-x86ia64io.h
+++ b/drivers/input/serio/i8042-x86ia64io.h
@@ -158,6 +158,13 @@
 			DMI_MATCH(DMI_PRODUCT_NAME, "Sentia"),
 		},
 	},
+	{
+		.ident = "Sharp Actius MM20",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "PC-MM20 Series"),
+		},
+	},
 	{ }
 };