meson: move flashstubs inclusion for organization reasons

Author: perigoso

src/target/meson.build

@@ -29,10 +29,10 @@
 # OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-target_common_includes = include_directories('.')
-
 subdir('flashstub')
 
+target_common_includes = include_directories('.')
+
 target_common_sources = files(
 	'adi.c',
 	'adiv5.c',