We don't DEPEND on openssl but configure will try to use it if
pkg-config thinks it might be installed. This can lead to failing
and/or nondeterministic builds, so let's force it off.
(From OE-Core rev: 1cdcd754651f8d519ac8e4ba0d241d784e2a0090)
Signed-off-by: Phil Blundell <pb@pbcl.net>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>