umbrello: add PCKAGECONFIG for clang - enabled if meta-clang is in layers

Signed-off-by: Andreas Müller <schnitzeltony@gmail.com>

recipes-kde/apps/umbrello/umbrello.bb

@@ -37,6 +37,12 @@ SRC_URI[sha256sum] = "c34a5f6ca945dd409921903abd2e0078b6a056a0d221d59674980ce424
 
 EXTRA_OECMAKE += "-DBUILD_KF5=1"
 
+PACKAGECONFIG ?= " \
+    ${@bb.utils.contains('BBFILE_COLLECTIONS', 'clang-layer', 'clang', '', d)} \
+"
+
+PACKAGECONFIG[clang] = ",,clang"
+
 FILES_${PN} += " \
     ${datadir}/kxmlgui5 \
     ${datadir}/umbrello5 \