Use get_frame_register_value instead of deprecated_frame_register_read

Use get_frame_register_value instead of deprecated_frame_register_read

This patch calls get_frame_register_value instead of
deprecated_frame_register_read, so that we can pass
value_contents_for_printing to val_print.  Both
get_frame_register_value and deprecated_frame_register_read call
frame_unwind_register_value indirectly, so no functionality is changed
by this patch.

gdb:

2016-11-08  Yao Qi  <yao.qi@linaro.org>

	* mt-tdep.c (mt_registers_info): Call
	get_frame_register_value instead of
	deprecated_frame_register_read.
	* sh64-tdep.c (sh64_do_register): Likewise.