Remove the dependency on 'declarative' from multimedia/qt5-phonon4

USE_QT5=declarative aka Qt Quick1 has been put to rest upstream [1], and
is no longer shipped with Qt5 [that's why it has been kept at 5.5.1 while the
rest of Qt has been updated to 5.6.1].

Similar to arch [2] and debian [3] also get rid of it as a dependency for
qt5-phonon4.

[1] http://permalink.gmane.org/gmane.comp.lib.qt.releasing/1973
[2] https://git.archlinux.org/svntogit/packages.git/commit/trunk?h=packages/phonon&id=1e16901aa3991d10e94906316258759be8e6b3d7
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=824957

Reviewed by:	rakuco
Approved by:	rakuco (mentor)
Differential Revision:	https://reviews.freebsd.org/D8163

multimedia/qt5-phonon4/Makefile

@@ -2,6 +2,7 @@
 
 PORTNAME=	phonon
 PORTVERSION=	4.9.0
+PORTREVISION=	1
 CATEGORIES=	multimedia
 MASTER_SITES=	KDE/stable/${PORTNAME}/${PORTVERSION}
 PKGNAMEPREFIX=	qt5-
@@ -16,11 +17,12 @@ LICENSE=	LGPL21
 BUILD_DEPENDS=	${LOCALBASE}/share/ECM/cmake/ECMConfig.cmake:devel/extra-cmake-modules
 
 USES=		cmake:outsource pathfix tar:xz
-USE_QT5=	core dbus declarative gui opengl widgets \
+USE_QT5=	core dbus gui opengl widgets \
 		buildtools_build qmake_build
 CMAKE_ARGS=	-DPHONON_INSTALL_QT_EXTENSIONS_INTO_SYSTEM_QT:BOOL=TRUE \
 		-DPHONON_NO_PLATFORMPLUGIN:BOOL=TRUE \
 		-DPHONON_BUILD_DESIGNER_PLUGIN:BOOL=OFF \
+		-DPHONON_BUILD_DECLARATIVE_PLUGIN:BOOL=OFF \
 		-DPHONON_BUILD_PHONON4QT5=ON
 USE_LDCONFIG=	yes