classes/base: set do_unpack dependencies for rpm files
If we're unpacking any rpm (not just .src.rpm) then we'll need to call
rpm2cpio.sh. As of OE-Core rev
a7da1aade118d1ccf1b286f82556cd9f706bd2a4
that script no longer uses file-native, but there is a chance that the
rpm file will be compressed internally using xz (for example, rpms from
Fedora) and therefore the script will need xzcat provided xz-native.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
