meta-qt5: update layer

Update to latest Qt 5.12 content

Task-number: QTBUG-73533
Change-Id: I48319668c2a31e6a2a9435716f729d38c8a992af
Reviewed-by: Samuli Piippo <samuli.piippo@qt.io>

scripts/manifest.xml

@@ -26,7 +26,7 @@
            path="sources/meta-openembedded"/>
   <project name="meta-qt5"
            remote="qtyocto"
-           revision="b9131d61d3f08669b493b5070811f2c617c8ee9f"
+           revision="7935b6bd03aafb7e238e623bdca832d1437b923a"
            path="sources/meta-qt5"/>
   <project name="meta-mingw"
            remote="qtyocto"