tcg-aarch64: Remove redundant CPU_TLB_ENTRY_BITS check

Removed from other targets in 56bbc2f967ce185fa1c5c39e1aeb5b68b26242e9.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Claudio Fontana <claudio.fontana@huawei.com>
Signed-off-by: Richard Henderson <rth@twiddle.net>
