drm/amdgpu: Remove duplicated argument in vcn_v4_0

Fix following coccicheck warning:
./drivers/gpu/drm/amd/amdgpu/vcn_v4_0.c:724:4-36: duplicated argument to & or |

Remove duplicated UVD_SUVD_CGC_GATE__SRE_H264_MASK.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>