recipes-kf5: Specify the libxml2 native dependency

Summary: Signed-off-by: Alistair Francis <alistair.francis@wdc.com>

Reviewers: vkrause

Reviewed By: vkrause

Differential Revision: https://phabricator.kde.org/D20473

recipes-plasma/ksysguard.inc

@@ -5,6 +5,7 @@ LIC_FILES_CHKSUM = "file://COPYING;md5=5c213a7de3f013310bd272cdb6eb7a24"
 PR = "r0"
 
 DEPENDS = " \
+    libxml2-native \
     kconfig \
     kcoreaddons \
     kdbusaddons \