OvmfPkg: Drop the ISA Floppy device support

OvmfPkg: Drop the ISA Floppy device support

REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1495

There is a plan to remove the IntelFrameworkModulePkg:
https://bugzilla.tianocore.org/show_bug.cgi?id=1605

And for driver:
IntelFrameworkModulePkg/Bus/Isa/IsaFloppyDxe

This patch proposes to drop the ISA Floppy device support in OVMF.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Ray Ni <ray.ni@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Hao Wu <hao.a.wu@intel.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
Tested-by: Anthony PERARD <anthony.perard@citrix.com>