Input: cros_ec_keyb - switch to SPDX identifier

Adopt the SPDX license identifier headers to ease license compliance
management.
Signed-off-by: NEnric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/cros_ec_keyb.c

-/*
- * ChromeOS EC keyboard driver
- *
- * Copyright (C) 2012 Google, Inc
- *
- * This software is licensed under the terms of the GNU General Public
- * License version 2, as published by the Free Software Foundation, and
- * may be copied, distributed, and modified under those terms.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * This driver uses the Chrome OS EC byte-level message-based protocol for
- * communicating the keyboard state (which keys are pressed) from a keyboard EC
- * to the AP over some bus (such as i2c, lpc, spi).  The EC does debouncing,
- * but everything else (including deghosting) is done here.  The main
- * motivation for this is to keep the EC firmware as simple as possible, since
- * it cannot be easily upgraded and EC flash/IRAM space is relatively
- * expensive.
- */
+// SPDX-License-Identifier: GPL-2.0
+// ChromeOS EC keyboard driver
+//
+// Copyright (C) 2012 Google, Inc.
+//
+// This driver uses the ChromeOS EC byte-level message-based protocol for
+// communicating the keyboard state (which keys are pressed) from a keyboard EC
+// to the AP over some bus (such as i2c, lpc, spi).  The EC does debouncing,
+// but everything else (including deghosting) is done here.  The main
+// motivation for this is to keep the EC firmware as simple as possible, since
+// it cannot be easily upgraded and EC flash/IRAM space is relatively
+// expensive.
 
 #include <linux/module.h>
 #include <linux/bitops.h>