OvmfPkg/QemuVideoDxe: Remove dependency on OptionRomPkg

OvmfPkg/QemuVideoDxe: Remove dependency on OptionRomPkg

Update the QemuVideoDxe driver to not depend on the
OptionRomPkg to support moving OptionRomPkg to the
edk2-platforms repository.

The only dependency on the OptionRomPkg is the use of
PcdDriverSupportedEfiVersion to set the version value in the
EFI Driver Supported EFI Version Protocol.

Quoting the UEFI-2.8 spec, "This protocol is required for EFI
drivers that are *on* PCI and other plug in cards" (emphasis ours).
However, QemuVideoDxe is always part of the OVMF platform firmware,
and is never read by PciBusDxe from the PCI ROM BAR of QEMU's
emulated graphics cards.

Since this protocol does not apply to QEMU environment, remove
both the PCD and the installation of the EFI Driver Supported EFI
Version Protocol.

Cc: Jordan Justen <jordan.l.justen@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>