ktap: Set MACHINE_ARCH because of ktap-module runtime dependency

* it's possible to exclude ktap-module dependency from siggen, but
  then we would need to exclude virtual/kernel and that doesn't work
  we would need to list all posisble providers as
  ktap->linux-yocto
  ktap->linux-foo
  ....

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>

meta-oe/recipes-kernel/ktap/ktap_0.4.bb

@@ -22,5 +22,5 @@ do_install() {
     install -m 0755 ${S}/ktap ${D}${bindir}/
 }
 
+PACKAGE_ARCH = "${MACHINE_ARCH}"
 RDEPENDS_${PN} = "kernel-module-ktapvm"
-