acer-wmi: Add DMI match for mail LED on Acer TravelMate 4200 series

The TM4200 series use the same method as the TM2490 series to control the
mail LED, so add a DMI based quirk for these laptops.

Signed-off-by: Carlos Corbacho <carlos@strangeworlds.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>
diff --git a/drivers/misc/acer-wmi.c b/drivers/misc/acer-wmi.c
index d7aea93..74d12b4 100644
--- a/drivers/misc/acer-wmi.c
+++ b/drivers/misc/acer-wmi.c
@@ -273,6 +273,15 @@
 	},
 	{
 		.callback = dmi_matched,
+		.ident = "Acer TravelMate 4200",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Acer"),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TravelMate 4200"),
+		},
+		.driver_data = &quirk_acer_travelmate_2490,
+	},
+	{
+		.callback = dmi_matched,
 		.ident = "Medion MD 98300",
 		.matches = {
 			DMI_MATCH(DMI_SYS_VENDOR, "MEDION"),