x86/asm: Annotate relocate_kernel_{32,64}.c

There are functions in relocate_kernel_{32,64}.c which are not
annotated. This makes automatic annotations on them rather hard. So
annotate all the functions now.

Note that these are not C-like functions, so FUNC is not used. Instead
CODE markers are used. Also the functions are not aligned, so the
NOALIGN versions are used:

- SYM_CODE_START_NOALIGN
- SYM_CODE_START_LOCAL_NOALIGN
- SYM_CODE_END

The result is:
  0000   108 NOTYPE  GLOBAL DEFAULT    1 relocate_kernel
  006c   165 NOTYPE  LOCAL  DEFAULT    1 identity_mapped
  0146   127 NOTYPE  LOCAL  DEFAULT    1 swap_pages
  0111    53 NOTYPE  LOCAL  DEFAULT    1 virtual_mapped

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Alexios Zavras <alexios.zavras@intel.com>
Cc: Allison Randal <allison@lohutok.net>
Cc: Enrico Weigelt <info@metux.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-arch@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20191011115108.12392-4-jslaby@suse.cz