hw/i386/pc: Set "normal" boot device order in pc_basic_device_init()

hw/i386/pc: Set "normal" boot device order in pc_basic_device_init()

The boot device order may change during the lifetime of a VM. Usually, the
"normal" order is set once during machine init(). However, if a user specifies
`-boot once=...`, the "normal" order is overwritten by the "once" order just
before machine_done, and a reset handler is registered which restores the
"normal" order during the next reset.

In the next patch, pc_cmos_init() will be inlined into pc_cmos_init_late() which
runs during machine_done. This means that the "once" boot order would be
overwritten again with the "normal" boot order -- which renders the user's
choice ineffective. Fix this by setting the "normal" boot order in
pc_basic_device_init() which already registers the boot_set() handler.

Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Message-Id: <20240303185332.1408-4-shentey@gmail.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>