anv/cmd_buffer: Enable a CS stall workaround for Sky Lake gt4
anv/cmd_buffer: Enable a CS stall workaround for Sky Lake gt4

This fixes hangs in Dota2

Reviewed-by: Kenneth Graunke <bd2562f754ec92342f93f61c25d731e290a2ffa8@whitecape.org>
Cc: "12.0 13.0" <59f39c0db42d4479a46b02d4d2bc11120e37bb44@lists.freedesktop.org>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler