OvmfPkg: Use TdInfo instead of fw_cfg to get cpu count in TDVF

[sunceping]

Currently TDVF gets cpu count information via fw_cfg, but this information can also be retrieved by calling of TdCall.TdInfo.

And TdCall is responded by tdx-module which is trust. So, from the security perspective we shall use TdCall.Tdinfo instead of fw_cfg.

Cc: Erdem Aktas [email protected]
Cc: Jiewen Yao [email protected]
Cc: Min Xu [email protected]
Cc: Gerd Hoffmann [email protected]
Cc: Elena Reshetova [email protected]
Signed-off-by: Ceping Sun [email protected]

Description

<Include a description of the change and why this change was made.>

<For each item, place an "x" in between [ and ] if true. Example: [x] (you can also check items in GitHub UI)>

<Create the PR as a Draft PR if it is only created to run CI checks.>

<Delete lines in <> tags before creating the PR.>

• Breaking change?
  • Breaking change - Does this PR cause a break in build or boot behavior?
  • Examples: Does it add a new library class or move a module to a different repo.
• Impacts security?
  • Security - Does this PR have a direct security impact?
  • Examples: Crypto algorithm change or buffer overflow fix.
• Includes tests?
  • Tests - Does this PR include any explicit test code?
  • Examples: Unit tests or integration tests.

How This Was Tested

<Describe the test(s) that were run to verify the changes.>

Integration Instructions

<Describe how these changes should be integrated. Use N/A if nothing is required.>