autoconf-archive: inherit allarch and fix package splitting

autoconf-archive: inherit allarch and fix package splitting

autoconf-archive is a set of common m4 macros, it should be allarch,
just like it is on other distros.

Also fix package splitting. With current package splitting,
autoconf-archive itself contains almost nothing, the m4 macros are
contained in its dev package. However, autoconf-archive should
contain those m4 marcos itself.

Signed-off-by: Chen Qi <Qi.Chen@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>