qt4: package static libraries correctly to fix warnings

qt4: package static libraries correctly to fix warnings

WARNING: QA Issue: non -staticdev package contains static .a library: qt4-demos path '/work/i586-poky-linux/qt4-x11-free-4.7.4-r39.7/packages-split/qt4-demos/usr/bin/qt4/demos/shared/libdemo_shared.a'
WARNING: QA Issue: non -staticdev package contains static .a library: qt4-examples path '/work/i586-poky-linux/qt4-x11-free-4.7.4-r39.7/packages-split/qt4-examples/usr/bin/qt4/examples/tools/plugandpaint/plugins/libpnp_basictools.a'
(From OE-Core rev: d4f1ef6b8297826230a68e535098709d07de1f48)

Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>