x86: Add support for specifying an initrd with the zboot command

This change finishes plumbing the initrd support built into the zboot
mechanism out to the command interface.

It also fixes a bug in the command declaration where the kernel size could
be passed as an optional second parameter but not enough arguments were
allowed.

Signed-off-by: Gabe Black <gabeblack@chromium.org>
1 file changed