kdesignerplugin: fix cross-build support in cmake macro.

Apply to (cross)build this package itself and use it from other buildings.

srcpkgs/kdesignerplugin/patches/kdesignerplugin-on-crossbuild.patch

@@ -0,0 +1,20 @@
+On cross-build, use the host's binary.
+Apply to both cross-build kdesignerplugin's package and use its package from others.
+--- KF5DesignerPluginMacros.cmake.ORIG
++++ KF5DesignerPluginMacros.cmake
+@@ -51,9 +51,14 @@
+     get_filename_component(basename ${input} NAME_WE)
+     set(source ${CMAKE_CURRENT_BINARY_DIR}/${basename}widgets.cpp)
+ 
++    set(KGENDESIGNERPLUGIN_LOCATION KF5::kgendesignerplugin)
++    if(CMAKE_CROSSCOMPILING)
++        set(KGENDESIGNERPLUGIN_LOCATION /usr/bin/kgendesignerplugin)
++    endif()
++
+     # create source file from the .widgets file
+     add_custom_command(OUTPUT ${source}
+-        COMMAND KF5::kgendesignerplugin
++        COMMAND ${KGENDESIGNERPLUGIN_LOCATION}
+         ARGS -o ${source} ${input}
+         MAIN_DEPENDENCY ${input})
+ 

srcpkgs/kdesignerplugin/template

@@ -1,7 +1,7 @@
 # Template file for 'kdesignerplugin'
 pkgname=kdesignerplugin
 version=5.43.0
-revision=2
+revision=3
 build_style=cmake
 configure_args="-DBUILD_TESTING=OFF"
 hostmakedepends="extra-cmake-modules"
@@ -19,14 +19,6 @@ if [ -n "$CROSS_BUILD" ]; then
 	configure_args+=" -DMEINPROC5_EXECUTABLE=/usr/bin/meinproc5"
 fi
 
-post_configure() {
-	if [ -n "$CROSS_BUILD" ]; then
-		# Hack to use host's kgendesignerplugin
-		find build/src/CMakeFiles -name "*.make" -exec sed -i "{}" \
-			-e "s;KF5::\(kgendesignerplugin\);/usr/bin/\1;" \;
-	fi
-}
-
 kgendesignerplugin_package() {
 	short_desc+=" - tool"
 	pkg_install() {