security_flags.inc: fix flags missing from SDK toolchain
The security flags were missing from the SDK toolchain
because they were added specifically to class-target.
Add them to class-cross-canadian as well (since the SDK environment
file is created from cross-canadian target flags).
Signed-off-by: Tom Hochstein <tom.hochstein@nxp.com> Signed-off-by: Antoine Manache <a.manache@gmail.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
