UPSTREAM: HID: elan: Add support for ELAN SB974D touchpad

Elan SB974D touchpad uses ELAN_MT_I2C format to send HID reports. Add an
entry to match for the device and parse its vendor specific format.

Bug: 458291401
Change-Id: Ia63cc4a2c9929ecee297e6608e522aff957363ae
Signed-off-by: Damien Dejean <damiendejean@google.com>
Signed-off-by: Kornel Dulęba <korneld@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
(cherry picked from commit 55ce1858848132ed074fe907f00b5ce1ccab0ce1)

drivers/hid/hid-elan.c

diff --git a/drivers/hid/hid-elan.c b/drivers/hid/hid-elan.c
index 76d93fc4..0190ad5 100644
--- a/drivers/hid/hid-elan.c
+++ b/drivers/hid/hid-elan.c
@@ -513,6 +513,7 @@ static const struct hid_device_id elan_devices[] = {
 	{ HID_USB_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_HP_X2_10_COVER),
 	  .driver_data = ELAN_HAS_LED },
 	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_TOSHIBA_CLICK_L9W) },
+	{ HID_I2C_DEVICE(USB_VENDOR_ID_ELAN, USB_DEVICE_ID_SB974D) },
 	{ }
 };
 MODULE_DEVICE_TABLE(hid, elan_devices);

drivers/hid/hid-ids.h

diff --git a/drivers/hid/hid-ids.h b/drivers/hid/hid-ids.h
index 25eb5cc..3a6f5b7 100644
--- a/drivers/hid/hid-ids.h
+++ b/drivers/hid/hid-ids.h
@@ -441,6 +441,7 @@
 #define USB_DEVICE_ID_EDIFIER_QR30	0xa101	/* EDIFIER Hal0 2.0 SE */
 
 #define USB_VENDOR_ID_ELAN		0x04f3
+#define USB_DEVICE_ID_SB974D            0x0400
 #define USB_DEVICE_ID_TOSHIBA_CLICK_L9W	0x0401
 #define USB_DEVICE_ID_HP_X2		0x074d
 #define USB_DEVICE_ID_HP_X2_10_COVER	0x0755