Way back in aba6488e0b, a bunch of signal
defines were changed to TARGET_SIGNAL_xxx. For d10v, the transition was
incomplete which lead to sim_stop_reason using the new set but sim_resume
still using the old set. Which meant in some cases, the sim would never
actually stop.
Convert all the remaining SIGxxx defines in here to TARGET_SIGNAL_xxx.
This has the nice side effect of fixing the testsuite.