x86 was using additional CPU_DUMP_* flags, so make that configurable in
CPUClass::reset_dump_flags.
This adds reset logging for alpha, unicore32 and xtensa.
Acked-by: Michael Walle <michael@walle.cc> (for lm32)
Reviewed-by: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andreas Färber <afaerber@suse.de>