The PN == BPN test was designed to exclude native/nativesdk but also unfortunately
excludes multilib unintentionally. This change fixes this and allows multilib images
with alternatives to funciton correctly.
[YOCTO #2214]
(From OE-Core rev: 2878d19c4e19d76cb8be15825c40ff03f25f35f5)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>