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>

sound/usb/6fire/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 snd-usb-6fire-objs += chip.o comm.o midi.o control.o firmware.o pcm.o
 obj-$(CONFIG_SND_USB_6FIRE) += snd-usb-6fire.o
 

sound/usb/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 # ALSA USB drivers
 
 menuconfig SND_USB

sound/usb/bcd2000/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 snd-bcd2000-y := bcd2000.o
 
 obj-$(CONFIG_SND_BCD2000) += snd-bcd2000.o

sound/usb/caiaq/Makefile

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 snd-usb-caiaq-y := device.o audio.o midi.o control.o
 snd-usb-caiaq-$(CONFIG_SND_USB_CAIAQ_INPUT) += input.o
 

sound/usb/hiface/Makefile

@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
 snd-usb-hiface-objs := chip.o pcm.o
 obj-$(CONFIG_SND_USB_HIFACE) += snd-usb-hiface.o

sound/usb/line6/Kconfig

@@ -1,3 +1,4 @@
+# SPDX-License-Identifier: GPL-2.0-only
 config SND_USB_LINE6
 	tristate
 	select SND_RAWMIDI

sound/usb/misc/Makefile

@@ -1,2 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
 snd-ua101-objs := ua101.o
 obj-$(CONFIG_SND_USB_UA101) += snd-ua101.o