Add LINK_PRIVATE_LIBRARIES to calamares_add_plugin.

CalamaresAddPlugin.cmake

@@ -6,7 +6,7 @@ function( calamares_add_plugin )
     set( NAME ${ARGV0} )
     set( options NO_INSTALL SHARED_LIB )
     set( oneValueArgs NAME TYPE EXPORT_MACRO RESOURCES )
-    set( multiValueArgs SOURCES UI LINK_LIBRARIES COMPILE_DEFINITIONS )
+    set( multiValueArgs SOURCES UI LINK_LIBRARIES LINK_PRIVATE_LIBRARIES COMPILE_DEFINITIONS )
     cmake_parse_arguments( PLUGIN "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN} )
     set( PLUGIN_NAME ${NAME} )
     set( PLUGIN_DESTINATION ${CMAKE_INSTALL_LIBDIR}/calamares/modules/${PLUGIN_NAME} )
@@ -22,6 +22,7 @@ function( calamares_add_plugin )
     if( NOT CMAKE_BUILD_TYPE STREQUAL "Release" )
         message( "   ${Green}TYPE:${ColorReset} ${PLUGIN_TYPE}" )
         message( "   ${Green}LINK_LIBRARIES:${ColorReset} ${PLUGIN_LINK_LIBRARIES}" )
+        message( "   ${Green}LINK_PRIVATE_LIBRARIES:${ColorReset} ${PLUGIN_LINK_PRIVATE_LIBRARIES}" )
 #        message( "   ${Green}SOURCES:${ColorReset} ${PLUGIN_SOURCES}" )
 #        message( "   ${Green}UI:${ColorReset} ${PLUGIN_UI}" )
 #        message( "   ${Green}EXPORT_MACRO:${ColorReset} ${PLUGIN_EXPORT_MACRO}" )
@@ -64,6 +65,10 @@ function( calamares_add_plugin )
         list( APPEND calamares_add_library_args "LINK_LIBRARIES" "${PLUGIN_LINK_LIBRARIES}" )
     endif()
 
+    if( PLUGIN_LINK_PRIVATE_LIBRARIES )
+        list( APPEND calamares_add_library_args "LINK_PRIVATE_LIBRARIES" "${PLUGIN_LINK_PRIVATE_LIBRARIES}" )
+    endif()
+
     if( PLUGIN_COMPILE_DEFINITIONS )
         list( APPEND calamares_add_library_args "COMPILE_DEFINITIONS" ${PLUGIN_COMPILE_DEFINITIONS} )
     endif()