Now the arm_ld*_code functions are only used at translate time we can
just pass down to translator_ld functions.

Signed-off-by: Emilio G. Cota <cota@braap.org>
[AJB: convert from plugin_insn_append to translator_ld]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>