qemu: command: Setup floppy drives via -device for blockdev

qemu: command: Setup floppy drives via -device for blockdev

To allow referring to the drives via the QOM id we need to setup the
floppy drives with a proper ID. This means that -device should be used
for them.

There are the following quirks:
- FDC needs to be instantiated prior to any floppy device
- floppy drive specified via -device does not support 'bootindex'
    (hacked around by passing bootindexA=1 to the FDC)

Signed-off-by: Peter Krempa <pkrempa@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>