ArmVirtPkg: revert "ArmVirtPkg: add QemuFwCfgToPcdDxe"

ArmVirtPkg: revert "ArmVirtPkg: add QemuFwCfgToPcdDxe"

This reverts git commit d2733aa9 (SVN r18042), because it is empty now.
The original problem:

  Many universal DXE drivers in edk2 can be controlled by setting dynamic
  PCDs. Such a PCD must be set before the consumer DXE driver is
  dispatched.

should be hereafter solved similarly to how
OvmfPkg/Library/SmbiosVersionLib is plugged into
MdeModulePkg/Universal/SmbiosDxe now (originally suggested by Jordan
Justen <jordan.l.justen@intel.com>).

Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Wei Huang <wei@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@18177 6f19259b-4bc3-4df7-8a09-765794883524