radeonsi: don't set CB_COLOR1_INFO for dual src blending
radeonsi: don't set CB_COLOR1_INFO for dual src blending

Vulkan doesn't do this. The reason may be that CB_COLOR1_INFO.SOURCE_FORMAT
from NI was moved to SPI_SHADER_COL_FORMAT for SI.

I asked CB guys about this 2 days ago and they still haven't replied.

Reviewed-by: Nicolai Hähnle <0d0be6cf5ad662651be2dc5dfd44aa2b09d4c1cc@amd.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler