treewide: Add SPDX license identifier - Makefile/Kconfig

Add SPDX license identifiers to all Make/Kconfig files which:

 - Have no license information of any form

These files fall under the project license, GPL v2 only. The resulting SPDX
license identifier is:

  GPL-2.0-only

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/hwmon/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Hardware monitoring chip drivers configuration
 #

drivers/hwmon/occ/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # On-Chip Controller configuration
 #

drivers/hwmon/occ/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 occ-hwmon-common-objs := common.o sysfs.o
 occ-p8-hwmon-objs := p8_i2c.o
 occ-p9-hwmon-objs := p9_sbe.o

drivers/hwmon/pmbus/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # PMBus chip drivers configuration
 #