ArmVirtPkg: set default for PcdSmbiosDocRev

ArmVirtPkg: set default for PcdSmbiosDocRev

When MdeModulePkg/Universal/SmbiosDxe is instructed to compose & install
an SMBIOS 3.0 entry point, it keys the Docrev (specification document
revision) field of that structure off of PcdSmbiosDocRev. An upcoming
OvmfPkg patch will have OvmfPkg/Library/SmbiosVersionLib set this PCD
dynamically. Because we use that driver in the ArmVirtQemu.dsc platform,
we must provide a default for the dynamic PCD.

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@18181 6f19259b-4bc3-4df7-8a09-765794883524