[h264e]: add SEI writing

1. write prep/codec/rc cfg to SEI
2. mpi_enc_test add SEI writting test
3. write SEI one sequence once defaultly

Change-Id: I7dd00a20afe101d7ddf17c875f0704d91a8fea2b
Signed-off-by: Lin Kesheng <lks@rock-chips.com>

test/mpi_enc_test.c

@@ -657,6 +657,7 @@ MPP_RET test_mpp_setup(MpiEncTestData *p)
     }
 
     /* optional */
+    p->sei_mode = MPP_ENC_SEI_MODE_ONE_SEQ;
     ret = mpi->control(ctx, MPP_ENC_SET_SEI_CFG, &p->sei_mode);
     if (ret) {
         mpp_err("mpi control enc set sei cfg failed ret %d\n", ret);