Functions.cmake: add missing dependency to *.keywords.

Due to this missing dependency, when a xxx.keyword file was modified, the files built from it were not rebuilt

CMakeModules/Functions.cmake

@@ -45,6 +45,7 @@ function( make_lexer outputTarget inputFile outHeaderFile outCppFile enum )
            ${outHeaderFile} and
            ${outCppFile} from
            ${inputFile}"
+        DEPENDS ${inputFile}
         )
 
     add_custom_target( ${outputTarget}

common/pcb.keywords

@@ -2,7 +2,7 @@
 # This program source code file is part of KiCad, a free EDA CAD application.
 #
 # Copyright (C) 2012 CERN.
-# Copyright (C) 2017 KiCad Developers, see AUTHORS.txt for contributors.
+# Copyright (C) 2019 KiCad Developers, see AUTHORS.txt for contributors.
 #
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License