[binutils-gdb] sim: fix sim-hardware configure option

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT 30452bbe7e68581cdb0cd5004e6c4d4d5c9536e8 ***

Author: Mike Frysinger <vapier@gentoo.org>
Branch: master
Commit: 30452bbe7e68581cdb0cd5004e6c4d4d5c9536e8

sim: fix sim-hardware configure option
The current default handling for the --enable-sim-hardware option ends up
forcing the value to whatever is set as the first argument when calling
the macro (by virtue of how autoconf works).  Relocate the setup code to
the 4th parameter of the AC_ARG_ENABLE macro to fix it.

This was caused by the simplification work in 1517bd274290e06af498ef7e49.

Reported-by: Hans-Peter Nilsson <hans-peter.nilsson@axis.com>