target/mips: Convert to CPUClass::tlb_fill

target/mips: Convert to CPUClass::tlb_fill

Note that env->active_tc.PC is removed from the qemu_log as that value
is garbage.  The PC isn't recovered until cpu_restore_state, called from
cpu_loop_exit_restore, called from do_raise_exception_err.

Cc: Aleksandar Markovic <amarkovic@wavecomp.com>
Cc: Aleksandar Rikalo <arikalo@wavecomp.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>