Input: stmfts - fix the MODULE_LICENSE() string

Replace the bogus "GPL v2" with "GPL" as MODULE_LICNSE() string. The
value does not declare the module's exact license, but only lets the
module loader test whether the module is Free Software or not.

See commit bf7fbeeae6 ("module: Cure the MODULE_LICENSE "GPL" vs.
"GPL v2" bogosity") in the details of the issue. The fix is to use
"GPL" for all modules under any variant of the GPL.

Signed-off-by: David Heidelberg <david@ixit.cz>
Link: https://patch.msgid.link/20260409-stmfts5-v4-1-64fe62027db5@ixit.cz
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/touchscreen/stmfts.c

@@ -807,4 +807,4 @@ module_i2c_driver(stmfts_driver);
 
 MODULE_AUTHOR("Andi Shyti <andi.shyti@samsung.com>");
 MODULE_DESCRIPTION("STMicroelectronics FTS Touch Screen");
-MODULE_LICENSE("GPL v2");
+MODULE_LICENSE("GPL");