The "includes" variable in the app/meson.build file was ignored when
building the executable, meaning that apps couldn't pass additional
include paths directly back. Fix this to align with drivers and libs.
Fixes: fa036e70d794 ("app: generalize meson build")
Cc: stable@dpdk.org
Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Reviewed-by: David Marchand <david.marchand@redhat.com>
64fd212430