HID: add multi-input quirk for IDC6680 touchscreen

The Ideacom 6680 touchscreen is found in the Dell Latitude 2100. It
has two USB descriptors, the first of which has two input reports. The
HID_QUIRK_MULTI_INPUT quirk is needed to keep the correct maximum
value for ABS_X/ABS_Y (8191 instead of 65535).
Signed-off-by: Nicholas Bishop <nbishop@neverware.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-ids.h

@@ -533,6 +533,7 @@
 #define USB_VENDOR_ID_IDEACOM		0x1cb6
 #define USB_DEVICE_ID_IDEACOM_IDC6650	0x6650
 #define USB_DEVICE_ID_IDEACOM_IDC6651	0x6651
+#define USB_DEVICE_ID_IDEACOM_IDC6680	0x6680
 
 #define USB_VENDOR_ID_ILITEK		0x222a
 #define USB_DEVICE_ID_ILITEK_MULTITOUCH	0x0001

drivers/hid/usbhid/hid-quirks.c

@@ -99,6 +99,7 @@ static const struct hid_blacklist {
 	{ USB_VENDOR_ID_HP, USB_PRODUCT_ID_HP_LOGITECH_OEM_USB_OPTICAL_MOUSE_0A4A, HID_QUIRK_ALWAYS_POLL },
 	{ USB_VENDOR_ID_HP, USB_PRODUCT_ID_HP_LOGITECH_OEM_USB_OPTICAL_MOUSE_0B4A, HID_QUIRK_ALWAYS_POLL },
 	{ USB_VENDOR_ID_HP, USB_PRODUCT_ID_HP_PIXART_OEM_USB_OPTICAL_MOUSE, HID_QUIRK_ALWAYS_POLL },
+	{ USB_VENDOR_ID_IDEACOM, USB_DEVICE_ID_IDEACOM_IDC6680, HID_QUIRK_MULTI_INPUT },
 	{ USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_C007, HID_QUIRK_ALWAYS_POLL },
 	{ USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_C077, HID_QUIRK_ALWAYS_POLL },
 	{ USB_VENDOR_ID_LOGITECH, USB_DEVICE_ID_LOGITECH_KEYBOARD_G710_PLUS, HID_QUIRK_NOGET },