target/arm: Remove unused allocation_tag_mem() argument

target/arm: Remove unused allocation_tag_mem() argument

The allocation_tag_mem() function takes an argument tag_size,
but it never uses it. Remove the argument. In mte_probe_int()
in particular this also lets us delete the code computing
the value we were passing in.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>