fix #4625: restore SMBIOS type 0 table defaults

fix #4625: restore SMBIOS type 0 table defaults

Commit 4cb94f20b0 ("OvmfPkg/SmbiosPlatformDxe: use PcdFirmware*") in
the edk2 submodule made the switch from hard coded values for the
SMBIOS type 0 table to using those defined in the PCD (Platform
Configuration Database). But this changed the value for the vendor
from "EFI Development Kit II / OVMF" to "EDK II" and made version and
release date "unknown". This can cause problems for hardware keys[0],
and the missing date can make Windows unhappy[1].

The PCD information can be specified during build. For the vendor,
just revert to the hardcoded value from before. This should be enough
to resolve the issue in [0]. For version and date, use sensible values
gathered from the build variables. The date format is mm/dd/yyyy while
the version is free-form according to [2], section 7.1.

[0]: https://bugzilla.proxmox.com/show_bug.cgi?id=4625
[1]: https://edk2.groups.io/g/devel/message/100922
[2]: https://www.dmtf.org/sites/default/files/standards/documents/DSP0134_3.2.0.pdf

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>