libsyncml: don't do out-of-tree builds manually

cmake.bbclass as of oe-core 783fb88 defaults to out-of-tree builds.  Use that
functionality instead of passing arguments to EXTRA_OECMAKE and _prepends.

Signed-off-by: Ross Burton <ross.burton@intel.com>
Reviewed-by: Otavio Salvador <otavio@ossystems.com.br>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/recipes-support/opensync/libsyncml_0.5.4.bb

@@ -13,17 +13,7 @@ SRC_URI[sha256sum] = "05d6513637adb1300a3a58b6e29d53ab6373c8f370807d0d925bae72b2
 
 inherit cmake pkgconfig
 
-EXTRA_OECMAKE += " . -B${WORKDIR}/build "
-
 PACKAGES += "${PN}-tools"
 
 FILES_${PN}-tools = "${bindir}"
 FILES_${PN} = "${libdir}/*.so.*"
-
-do_build_prepend() {
-    cd ${WORKDIR}/build
-}
-
-do_install_prepend() {
-    cd ${WORKDIR}/build
-}