i965/eu: set correct execution size in brw_NOP
i965/eu: set correct execution size in brw_NOP

v2: NOP should have an execsize of 1 (Matt)

Reviewed-by: Matt Turner <789b315743a28dd066a4ba1459c35951c291d8a6@gmail.com>
Reviewed-by: Topi Pohjolainen <749697f19798b7f640b17221fd283b903825f071@intel.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler