Fix sh64-elf sim, default hardware to off.

Fix sh64-elf sim, default hardware to off.

See nearby (previous) commit for the iq2000 sim; this similarly fails
at the dv_sockser_install declaration in sim/sh64/tconfig.in.  I'm
disabling simulator hardware to be consistent with the state before
94c63d78f (2013-03-23) and with the actions for the frv sim and the
iq2000 sim.  Make check-sim for sh64-elf shows no regressions (25
failures; 357 expected passes) compared to bf3d9781ec049 (before the
recent config.in regen, after sim-hardware mostly-enabled) and
eed23bb4a1 (before the sim-hardware mostly-enabled; 2013-03-23).

sim/sh64:
	* configure.ac: Default simulator hardware to off again
	without emitting errors when off or dv-sockser.o unavailable.
	* configure: Regenerate.