i965: Increase Sandybridge point size clamp in the clip state.
i965: Increase Sandybridge point size clamp in the clip state.

255.875 matches the hardware documentation.  Presumably this was a typo.

NOTE: This is a candidate for the 7.10 branch, along with
      commit 2bfc23fb86964e4153f57f2a56248760f6066033.

Reviewed-by: Eric Anholt <96f164ad4d9b2b0dacf8ebee2bb1eeb3aa69adf1@anholt.net>

benaadams/glsl-optimizer,djreep81/glsl-optimizer,adobe/glsl2agal,mapbox/glsl-optimizer,metora/MesaGLSLCompiler,mcanthony/glsl-optimizer,zz85/glsl-optimizer,mapbox/glsl-optimizer,dellis1972/glsl-optimizer,wolf96/glsl-optimizer,adobe/glsl2agal,zz85/glsl-optimizer,adobe/glsl2agal,jbarczak/glsl-optimizer,KTXSoftware/glsl2agal,KTXSoftware/glsl2agal,jbarczak/glsl-optimizer,KTXSoftware/glsl2agal,dellis1972/glsl-optimizer,bkaradzic/glsl-optimizer,benaadams/glsl-optimizer,zeux/glsl-optimizer,bkaradzic/glsl-optimizer,adobe/glsl2agal,tokyovigilante/glsl-optimizer,bkaradzic/glsl-optimizer,wolf96/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,benaadams/glsl-optimizer,wolf96/glsl-optimizer,zeux/glsl-optimizer,djreep81/glsl-optimizer,zeux/glsl-optimizer,bkaradzic/glsl-optimizer,zz85/glsl-optimizer,tokyovigilante/glsl-optimizer,mapbox/glsl-optimizer,jbarczak/glsl-optimizer,tokyovigilante/glsl-optimizer,zz85/glsl-optimizer,mapbox/glsl-optimizer,djreep81/glsl-optimizer,KTXSoftware/glsl2agal,benaadams/glsl-optimizer,KTXSoftware/glsl2agal,dellis1972/glsl-optimizer,mapbox/glsl-optimizer,zz85/glsl-optimizer,jbarczak/glsl-optimizer,benaadams/glsl-optimizer,dellis1972/glsl-optimizer,mcanthony/glsl-optimizer,tokyovigilante/glsl-optimizer,jbarczak/glsl-optimizer,wolf96/glsl-optimizer,zz85/glsl-optimizer,zeux/glsl-optimizer,tokyovigilante/glsl-optimizer,mcanthony/glsl-optimizer,djreep81/glsl-optimizer,mcanthony/glsl-optimizer,adobe/glsl2agal,metora/MesaGLSLCompiler,bkaradzic/glsl-optimizer,metora/MesaGLSLCompiler,djreep81/glsl-optimizer,zeux/glsl-optimizer,wolf96/glsl-optimizer,mcanthony/glsl-optimizer