bzip2/lzma: make config machinery an arch configurable

Impact: Bug fix (we should not show this menu on irrelevant architectures)

Make the config machinery to drive the gzip/bzip2/lzma selection
dependent on the architecture advertising HAVE_KERNEL_* so that we
don't display this for architectures where it doesn't matter.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>