tools/headers: Synchronize kernel ABI headers

After the SPDX license tags were added a number of tooling headers got out of
sync with their kernel variants, generating lots of build warnings.

Sync them:

- tools/arch/x86/include/asm/disabled-features.h,
tools/arch/x86/include/asm/required-features.h,
tools/include/linux/hash.h:

Remove the SPDX tag where the kernel version does not have it.

- tools/include/asm-generic/bitops/__fls.h,
tools/include/asm-generic/bitops/arch_hweight.h,
tools/include/asm-generic/bitops/const_hweight.h,
tools/include/asm-generic/bitops/fls.h,
tools/include/asm-generic/bitops/fls64.h,
tools/include/uapi/asm-generic/ioctls.h,
tools/include/uapi/asm-generic/mman-common.h,
tools/include/uapi/sound/asound.h,
tools/include/uapi/linux/kvm.h,
tools/include/uapi/linux/perf_event.h,
tools/include/uapi/linux/sched.h,
tools/include/uapi/linux/vhost.h,
tools/include/uapi/sound/asound.h:

Add the SPDX tag of the respective kernel header.

- tools/include/uapi/linux/bpf_common.h,
tools/include/uapi/linux/fcntl.h,
tools/include/uapi/linux/hw_breakpoint.h,
tools/include/uapi/linux/mman.h,
tools/include/uapi/linux/stat.h,

Change the tag to the kernel header version:

-/* SPDX-License-Identifier: GPL-2.0 */
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */

Also sync other header details:

- include/uapi/sound/asound.h:

Fix pointless end of line whitespace noise the header grew in this cycle.

- tools/arch/x86/lib/memcpy_64.S:

Sync the code and add tools/include/asm/export.h with dummy wrappers
to support building the kernel side code in a tooling header environment.

- tools/include/uapi/asm-generic/mman.h,
tools/include/uapi/linux/bpf.h:

Sync other details that don't impact tooling's use of the ABIs.

Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Ingo Molnar <mingo@kernel.org>