treewide: Add SPDX license identifier - Kbuild

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

Reported-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/alpha/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += unistd_32.h

arch/arc/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 obj-y += kernel/
 obj-y += mm/

arch/arc/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h

arch/arm/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += compat.h
 generic-y += current.h
 generic-y += early_ioremap.h

arch/arm64/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += bugs.h
 generic-y += delay.h
 generic-y += div64.h

arch/c6x/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += atomic.h
 generic-y += barrier.h
 generic-y += bugs.h

arch/c6x/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h

arch/csky/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += asm-offsets.h
 generic-y += bugs.h
 generic-y += compat.h

arch/csky/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h

arch/h8300/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += asm-offsets.h
 generic-y += barrier.h
 generic-y += bugs.h

arch/h8300/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h

arch/hexagon/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generic-y += ucontext.h

arch/ia64/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += syscall_table.h
 generic-y += compat.h
 generic-y += exec.h

arch/ia64/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += unistd_64.h

arch/m68k/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += syscall_table.h
 generic-y += barrier.h
 generic-y += compat.h

arch/m68k/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += unistd_32.h

arch/microblaze/include/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += syscall_table.h
 generic-y += barrier.h
 generic-y += bitops.h

arch/microblaze/include/uapi/asm/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 generated-y += unistd_32.h
 generic-y += ucontext.h

arch/mips/Kbuild

+# SPDX-License-Identifier: GPL-2.0
 # Fail on warnings - also for files referenced in subdirs
 # -Werror can be disabled for specific files using:
 # CFLAGS_<file.o> := -Wno-error

arch/mips/Kbuild.platforms

+# SPDX-License-Identifier: GPL-2.0
 # All platforms listed in alphabetic order
 
 platforms += alchemy