scripts: clean up IA-64 code

commit 0df8e970 upstream.

A little more janitorial work after commit cf8e8658 ("arch: Remove
Itanium (IA-64) architecture").

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nicolas Schier <nicolas@fjasle.eu>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>