kbuild: rpm-pkg: Add (elfutils-devel or libdw-devel) to BuildRequires

The dwarf.h header, which is included by
scripts/gendwarfksyms/gendwarfksyms.h, resides within elfutils-devel
or libdw-devel package.

This portion of the code is compiled under the condition that
CONFIG_GENDWARFKSYMS is enabled.

Consequently, add (elfutils-devel or libdw-devel) to BuildRequires to
prevent unforeseen compilation failures.

Fix follow possible error:
  In file included from scripts/gendwarfksyms/cache.c:6:
  scripts/gendwarfksyms/gendwarfksyms.h:6:10: fatal error: 'dwarf.h' file not found
      6 | #include <dwarf.h>
        |          ^~~~~~~~~

Link: https://lore.kernel.org/all/3e52d80d-0c60-4df5-8cb5-21d4b1fce7b7@suse.com/


Fixes: f2856884 ("tools: Add gendwarfksyms")
Suggested-by: Petr Pavlu <petr.pavlu@suse.com>
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Reviewed-by: Nicolas Schier <n.schier@avm.de>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>