ci: Build parallel port code for supported systems

Test building parallel port code for supported systems.

Unsupported systems are:

  * MSVC compiler (does not support GNU style inline asm)
  * macos operating system (no macos implementations for preprocessor
    macros DO_PPI_READ, DO_PPI_WRITE, ppi_claim, ppi_release)

This means the CI can test

  * native Linux builds (yes, even for arm systems)
  * native Windows builds using mingw

Untested at this time are the BSDs.

.github/workflows/build.yml

@@ -105,6 +105,7 @@ jobs:
           cmake
           -D BUILD_DOC=1
           -D DEBUG_CMAKE=1
+          -D HAVE_PARPORT=1
           -D HAVE_LINUXGPIO=1
           -D HAVE_LINUXSPI=1
           -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
@@ -169,6 +170,7 @@ jobs:
         run: >-
           cmake
           -D DEBUG_CMAKE=1
+          -D HAVE_PARPORT=1
           -D HAVE_LINUXGPIO=1
           -D HAVE_LINUXSPI=1
           -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
@@ -367,6 +369,7 @@ jobs:
           -G"MSYS Makefiles"
           -D DEBUG_CMAKE=1
           -D CMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}
+          -D HAVE_PARPORT=1
           -B build
       - name: Build
         run: cmake --build build