lttng-tools: Add missing DEPENDS on bison-native

This was being provided by other pieces of the dependency chain but is
specifically required by configure and could fail if those pieces come
from sstate. Fix such builds by adding the missing dependency.

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
(cherry picked from commit ba2587be)
Signed-off-by: Steve Sakoman <steve@sakoman.com>