package/qemu: add qemu host tools

Always build host qemu-tools e.g. qemu-img.
https://qemu.readthedocs.io/en/latest/tools/index.html

Signed-off-by: Thomas Devoogdt <thomas.devoogdt@gmail.com>
Reviewed-by: Thomas Huth <huth@tuxfamily.org>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/qemu/qemu.mk

@@ -390,6 +390,7 @@ define HOST_QEMU_CONFIGURE_CMDS
 		--disable-vnc-jpeg \
 		--disable-vnc-png \
 		--disable-vnc-sasl \
+		--enable-tools \
 		$(HOST_QEMU_OPTS)
 endef