arm/hafnium: don't exclude from world builds

Clang is large but this recipe builds on all hosts now, so we don't need
to exclude it.

Signed-off-by: Ross Burton <ross.burton@arm.com>
Signed-off-by: Jon Mason <jon.mason@arm.com>

meta-arm/recipes-bsp/hafnium/hafnium_2.12.0.bb

@@ -66,5 +66,3 @@ do_deploy() {
     cp -rf ${D}/firmware/* ${DEPLOYDIR}/
 }
 addtask deploy after do_install
-
-EXCLUDE_FROM_WORLD = "1"