Fix build failure in d10v sim

Fix build failure in d10v sim

While building all targets on Ubuntu 20.04/aarch64, I ran into the following
build error:

In file included from /usr/include/string.h:495,
                 from ../../bfd/bfd.h:48,
                 from ../../../../repos/binutils-gdb/sim/d10v/interp.c:4:
In function memset,
    inlined from sim_create_inferior at ../../../../repos/binutils-gdb/sim/d10v/interp.c:1146:3:
/usr/include/aarch64-linux-gnu/bits/string_fortified.h:71:10: error: __builtin_memset offset [33, 616] from the object at State is out of the bounds of referenced subobject regs with type reg_t[16] {aka short unsigned int[16]} at offset 0 [-Werror=array-bounds]
   71 |   return __builtin___memset_chk (__dest, __ch, __len, __bos0 (__dest));
      |          ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
cc1: all warnings being treated as errors
make[3]: *** [Makefile:558: interp.o] Error 1

The following patch fixes this.

sim/ChangeLog:

2021-05-12  Luis Machado  <luis.machado@linaro.org>

	* d10v/interp.c (sim_create_inferior): Fix memset call.