meta-yocto/qt4: Update bbappend to new version

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

diff --git a/meta-yocto/recipes-qt/qt4/qt4-x11-free_4.7.3.bbappend b/meta-yocto/recipes-qt/qt4/qt4-x11-free_4.7.4.bbappend
similarity index 100%
rename from meta-yocto/recipes-qt/qt4/qt4-x11-free_4.7.3.bbappend
rename to meta-yocto/recipes-qt/qt4/qt4-x11-free_4.7.4.bbappend