Fixed -dbus-linked when cross-compiling from Windows

Since Windows doesn't have pkg-config, it doesn't get -ldbus-1
added to the command line automatically like Linux does.  Code
was present to deal with this case, however it was only configured
to work when native-compiling Qt.  The flag was not added when
cross-compiling, meaning that -dbus-linked did not work correctly
in that case.  This patch changes the code to add the flag properly
in both cases.

Change-Id: I67881643bd658161f4929f3932859ccf636ca7a9
Task-number: QTBUG-29984
Reviewed-by: Thiago Macieira <[email protected]>
(cherry-picked from qtbase/c82b0815ec80b3750a110d47c68142bb448ddf56)
Reviewed-by: Oswald Buddenhagen <[email protected]>

Author: mattfischer

src/dbus/dbus.pro

@@ -6,6 +6,12 @@ CONFIG += link_pkgconfig
 DEFINES += QT_BUILD_DBUS_LIB \
     DBUS_API_SUBJECT_TO_CHANGE
 QMAKE_CXXFLAGS += $$QT_CFLAGS_DBUS
+
+isEmpty(QT_LIBS_DBUS) {
+    win32:CONFIG(debug, debug|release):QT_LIBS_DBUS += -ldbus-1d
+    else:QT_LIBS_DBUS += -ldbus-1
+}
+
 contains(QT_CONFIG, dbus-linked) { 
     LIBS_PRIVATE += $$QT_LIBS_DBUS
     DEFINES += QT_LINKED_LIBDBUS
@@ -25,8 +31,6 @@ win32 {
         -ladvapi32 \
         -lnetapi32 \
         -luser32
-    CONFIG(debug, debug|release):LIBS_PRIVATE += -ldbus-1d
-    else:LIBS_PRIVATE += -ldbus-1
 }
 include(../qbase.pri)
 PUB_HEADERS = qdbusargument.h \