Revert "ovmf: Fix CVE-2023-45237"

This reverts commit 6f8bdaad9d22e65108f859a695277ce1b20ef7c6.

his reverts commit 4c2d3e3.

The fix for CVE-2023-45237 causes ovmf firmware not support pxe boot
any more and no boot item in OVMF menu such as

    UEFI PXEv4 (MAC address)

It has not been fixed by ovmf upstream and an issue has been created on

tianocore/tianocore.github.io#82

Revert the fixes for now.

(From OE-Core rev: d3f399f54042efc6f4ca2092dd11819ae1f7c51f)

Signed-off-by: Kai Kang <[email protected]>
Signed-off-by: Steve Sakoman <[email protected]>