accel/tcg: Modify atomic_mmu_lookup() to use CPUState

accel/tcg: Modify atomic_mmu_lookup() to use CPUState

The goal is to (in the future) allow for per-target compilation of
functions in atomic_template.h whilst atomic_mmu_lookup() and cputlb.c
are compiled once-per user- or system mode.

Signed-off-by: Anton Johansson <anjo@rev.ng>
Message-Id: <20230912153428.17816-7-anjo@rev.ng>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
[rth: Use cpu->neg.tlb instead of cpu_tlb()]
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>