aco/ra: disallow s_cmpk with scc operand

Fixes: 2d6b0a4177 ("aco/optimizer: Optimize SOPC with literal to SOPK.")

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32545>

src/amd/compiler/aco_register_allocation.cpp

@@ -2091,6 +2091,7 @@ operand_can_use_reg(amd_gfx_level gfx_level, aco_ptr<Instruction>& instr, unsign
               gfx_level >= GFX10); /* sdata can be vcc */
    case Format::MUBUF:
    case Format::MTBUF: return idx != 2 || gfx_level < GFX12 || reg != scc;
+   case Format::SOPK: return idx != 0 || reg != scc;
    default:
       // TODO: there are more instructions with restrictions on registers
       return true;