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/platform/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 if X86
 source "drivers/platform/x86/Kconfig"
 endif

drivers/platform/chrome/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Platform support for Chrome OS hardware (Chromebooks and Chromeboxes)
 #

drivers/platform/chrome/wilco_ec/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 config WILCO_EC
 	tristate "ChromeOS Wilco Embedded Controller"
 	depends on ACPI && X86 && CROS_EC_LPC && CROS_EC_LPC_MEC

drivers/platform/goldfish/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 menuconfig GOLDFISH
 	bool "Platform support for Goldfish virtual devices"
 	depends on X86_32 || X86_64 || ARM || ARM64 || MIPS

drivers/platform/goldfish/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # Makefile for Goldfish platform specific drivers
 #

drivers/platform/mips/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # MIPS Platform Specific Drivers
 #

drivers/platform/mips/Makefile

@@ -1 +1,2 @@
+# SPDX-License-Identifier: GPL-2.0-only
 obj-$(CONFIG_CPU_HWMON) += cpu_hwmon.o

drivers/platform/olpc/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # OLPC XO platform-specific drivers
 #

drivers/platform/x86/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 #
 # X86 Platform Specific Drivers
 #