kate: use CLOCK_FREQ

(cherry picked from commit bd05cf845539dec9300ab7562b44f1098bb529cc)
Signed-off-by: Felix Paul Kühne <fkuehne@videolan.org>

modules/codec/kate.c

@@ -1170,7 +1170,8 @@ static subpicture_t *DecodePacket( decoder_t *p_dec, kate_packet *p_kp, block_t
     }
 
     p_spu->i_start = p_block->i_pts;
-    p_spu->i_stop = p_block->i_pts + INT64_C(1000000)*ev->duration*p_sys->ki.gps_denominator/p_sys->ki.gps_numerator;
+    p_spu->i_stop = p_block->i_pts + CLOCK_FREQ *
+        ev->duration * p_sys->ki.gps_denominator / p_sys->ki.gps_numerator;
     p_spu->b_ephemer = false;
     p_spu->b_absolute = false;