intel/compiler: Silence unused parameter warnings in vec4_tcs_visitor

intel/compiler: Silence unused parameter warnings in vec4_tcs_visitor

In file included from src/intel/compiler/brw_vec4_tcs.cpp:31:
src/intel/compiler/brw_vec4_tcs.h: In member function ‘virtual void brw::vec4_tcs_visitor::emit_urb_write_header(int)’:
src/intel/compiler/brw_vec4_tcs.h:74:43: warning: unused parameter ‘mrf’ [-Wunused-parameter]
   74 |    virtual void emit_urb_write_header(int mrf) {}
      |                                       ~~~~^~~
src/intel/compiler/brw_vec4_tcs.h: In member function ‘virtual brw::vec4_instruction* brw::vec4_tcs_visitor::emit_urb_write_opcode(bool)’:
src/intel/compiler/brw_vec4_tcs.h:75:57: warning: unused parameter ‘complete’ [-Wunused-parameter]
   75 |    virtual vec4_instruction *emit_urb_write_opcode(bool complete) { return NULL; }
      |                                                    ~~~~~^~~~~~~~

Reviewed-by: Matt Turner <mattst88@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4582>