tools/init-dom0less: Only seed legacy xenstore grants

tools/init-dom0less: Only seed legacy xenstore grants

The hardware domain is unable to seed a control domain, but we want the
control domain to use xenstore.  Rely on the hypervisor to seed dom0less
grant table entries for Xenstore, so this seeding is unnecessary.

However, that only works for the new xenstore late init.  The legacy
protocol which uses init-dom0less to populate the page still needs to
seed the grant.

Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>