target/arm: Pass MemOp to get_phys_addr_nogpc

Zero is the safe do-nothing value for callers to use.
Pass the value through from get_phys_addr_gpc and
get_phys_addr_with_space_nogpc.

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