[CHERRY-PICK] MsWheaPkg: Add EFIAPI to relevant functions [Rebase & FF]

[makubacki]

Description

MsWheaReportHandlerPei() is passed to ReportHwErrRecRouter() for the
MS_WHEA_ERR_REPORT_PS_FN value where that is defined as:

typedef
EFI_STATUS
(EFIAPI *MS_WHEA_ERR_REPORT_PS_FN)(
  IN MS_WHEA_ERROR_ENTRY_MD           *MsWheaEntryMD
  );

So, MsWheaReportHandlerPei() needs to include EFIAPI as well.

Similarly, MsWheaRscHandlerPei() needs EFIAPI due to the definition
of EFI_PEI_RSC_HANDLER_CALLBACK.

• Impacts functionality?
  • Functionality - Does the change ultimately impact how firmware functions?
  • Examples: Add a new library, publish a new PPI, update an algorithm, ...
• Impacts security?
  • Security - Does the change have a direct security impact on an application,
    flow, or firmware?
  • Examples: Crypto algorithm change, buffer overflow fix, parameter
    validation improvement, ...
• Breaking change?
  • Breaking change - Will anyone consuming this change experience a break
    in build or boot behavior?
  • Examples: Add a new library class, move a module to a different repo, call
    a function in a new library class in a pre-existing module, ...
• Includes tests?
  • Tests - Does the change include any explicit test code?
  • Examples: Unit tests, integration tests, robot tests, ...
• Includes documentation?
  • Documentation - Does the change contain explicit documentation additions
    outside direct code modifications (and comments)?
  • Examples: Update readme file, add feature readme file, link to documentation
    on an a separate Web page, ...

How This Was Tested

• Verified results from a GCC build that reported the issue before and after
  the change.

Integration Instructions

N/A

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 0% with 1 lines in your changes are missing coverage. Please review.

Project coverage is 12.13%. Comparing base (ba26b5d) to head (b31630c).

Files	Patch %	Lines
MsWheaPkg/MsWheaReport/Pei/MsWheaReportPei.c	0.00%	1 Missing ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##           release/202302     #443      +/-   ##
==================================================
- Coverage           12.13%   12.13%   -0.01%     
==================================================
  Files                 110      110              
  Lines               19022    19024       +2     
  Branches             1363     1363              
==================================================
  Hits                 2308     2308              
- Misses              16697    16699       +2     
  Partials               17       17              

Flag	Coverage Δ
HidPkg	2.80% <ø> (ø)
MfciPkg	38.25% <ø> (ø)
MsCorePkg	1.43% <ø> (ø)
MsWheaPkg	7.16% <0.00%> (-0.01%)	⬇️
XmlSupportPkg	25.41% <ø> (ø)

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