avcodec/mips: fix conflicting types error of ff_vc1_h_s_overlap_mmi.

In commit 975a1a8,function ff_vc1_h_s_overlap_mmi was refactored,
but the declaration in libavcodec/mips/vc1dsp_mips.h was unchanged.

Change-Id: I90beae683511622a0cc1130ab1660ac8669ec3ef
Signed-off-by: Shiyou Yin <yinshiyou-hf@loongson.cn>
Reviewed-by: Jerome Borsboom <jerome.borsboom@carpalis.nl>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/mips/vc1dsp_mips.h

@@ -169,7 +169,7 @@ void ff_vc1_inv_trans_8x8_dc_mmi(uint8_t *dest, ptrdiff_t linesize, int16_t *blo
 void ff_vc1_v_overlap_mmi(uint8_t *src, int stride);
 void ff_vc1_h_overlap_mmi(uint8_t *src, int stride);
 void ff_vc1_v_s_overlap_mmi(int16_t *top, int16_t *bottom);
-void ff_vc1_h_s_overlap_mmi(int16_t *left, int16_t *right);
+void ff_vc1_h_s_overlap_mmi(int16_t *left, int16_t *right, int left_stride, int right_stride, int flags);
 
 void ff_vc1_v_loop_filter4_mmi(uint8_t *src, int stride, int pq);
 void ff_vc1_h_loop_filter4_mmi(uint8_t *src, int stride, int pq);