Add 'qtwaylandcompositor' to the depends list

Required for qdoc to resolve cross-module links.

Change-Id: I5cfdb1b8076e6ab042ad4f426da3cd69e8746d63
Reviewed-by: Topi Reiniö <topi.reinio@theqtcompany.com>
Reviewed-by: Martin Smith <martin.smith@theqtcompany.com>

doc/config/qtdoc.qdocconf

@@ -66,7 +66,8 @@ depends += \
     qt3d \
     qtcanvas3d \
     qtwebview \
-    qtquickcontrols2
+    qtquickcontrols2 \
+    qtwaylandcompositor
 
 headerdirs  += ../src
 imagedirs   += ../src/images \