[vcpkg baseline][qca] Re-fix find pkgconfig using FindPkgConfig.cmake

[JackBoosY]

Continue PR #14058, use the FindPkgConfig.cmake fixed by cmake to solve the issue of finding the pkg-config script in perl in Windows (fixed by PR https://gitlab.kitware.com/cmake/cmake/-/merge_requests/5273).

Current configure result:

CMake Error at D:/downloads/tools/cmake-3.18.2-windows/cmake-3.18.2-win32-x86/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:165 (message):
  Could NOT find PkgConfig (missing: PKG_CONFIG_EXECUTABLE)

      Reason given by package: The command
        "D:/downloads/tools/perl/5.30.0.1/perl/bin/pkg-config" --version
      failed with output
        

Call Stack (most recent call first):
  D:/downloads/tools/cmake-3.18.2-windows/cmake-3.18.2-win32-x86/share/cmake-3.18/Modules/FindPackageHandleStandardArgs.cmake:458 (_FPHSA_FAILURE_MESSAGE)
  D:/downloads/tools/cmake-3.18.2-windows/cmake-3.18.2-win32-x86/share/cmake-3.18/Modules/FindPkgConfig.cmake:59 (find_package_handle_standard_args)
  C:/a/1/s/scripts/buildsystems/vcpkg.cmake:530 (_find_package)
  plugins/qca-nss/CMakeLists.txt:1 (find_package)

Fixed configure results:

-- Found PkgConfig: F:/vcpkg/downloads/tools/perl/5.30.0.1/perl/bin/pkg-config.bat (found version "0.26") 

Related: #12612.

[JackBoosY]

Required by FindPkgConfig.cmake.

[JackBoosY]

Required by FindPackageHandleStandardArgs.cmake.

[BillyONeal]

Thanks for your contribution!