build: use GNUInstallDirs where possible

Some installation destinations were already converted to the
GNUInstallDirs standard in e3cf4d0cf. This patch converts the share and
include directories (typically /usr/share and /usr/include respectively)
as well.

Type: improvement
Change-Id: Id481b16604f3f52203166a5c0647f43d6eb05239
Signed-off-by: Wim de With <wf@dewith.io>
diff --git a/src/cmake/library.cmake b/src/cmake/library.cmake
index 45b3944..a06a795 100644
--- a/src/cmake/library.cmake
+++ b/src/cmake/library.cmake
@@ -72,7 +72,7 @@
 	${CMAKE_CURRENT_BINARY_DIR}/${file}_types.h
 	${CMAKE_CURRENT_BINARY_DIR}/${file}_tojson.h
 	${CMAKE_CURRENT_BINARY_DIR}/${file}_fromjson.h
-	DESTINATION include/${lib}/${dir}
+	DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${lib}/${dir}
 	COMPONENT vpp-dev
       )
     endforeach()
@@ -96,7 +96,7 @@
       get_filename_component(dir ${file} DIRECTORY)
       install(
 	FILES ${file}
-	DESTINATION include/${lib}/${dir}
+	DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${lib}/${dir}
 	COMPONENT ${ARG_COMPONENT}-dev
       )
     endforeach()
@@ -111,7 +111,7 @@
     get_filename_component(dir ${file} DIRECTORY)
     install(
       FILES ${file}
-      DESTINATION include/${path}/${dir}
+      DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}/${path}/${dir}
       COMPONENT vpp-dev
     )
   endforeach()