sim/common: Fix warnings: "warning: implicit declaration of function..."

sim/common: Fix warnings: "warning: implicit declaration of function..."

During building of several cgen simulator's I notices the below
warnings.  Adding includes fixes these.

Including config.h allows stdio.h to properly configure itself to expose
asprintf().

The other warnings for abort, free, memset, strlen are trivial.

Warnings:

../../../binutils-gdb/sim/or1k/../common/sim-watch.c: In function ‘sim_watchpoint_install’:
../../../binutils-gdb/sim/or1k/../common/sim-watch.c:415:10: warning: implicit declaration of function ‘asprintf’; did you mean ‘vasprintf’? [-Wimplicit-function-declaration]
      if (asprintf (&name, "watch-%s-%s",
          ^~~~~~~~
          vasprintf

../../../binutils-gdb/sim/lm32/../common/hw-device.c: In function ‘hw_strdup’:
../../../binutils-gdb/sim/lm32/../common/hw-device.c:59:34: warning: implicit declaration of function ‘strlen’ [-Wimplicit-function-declaration]
       char *dup = hw_zalloc (me, strlen (str) + 1);
                                  ^~~~~~

../../../binutils-gdb/sim/lm32/../common/hw-events.c: In function ‘hw_event_queue_schedule’:
../../../binutils-gdb/sim/lm32/../common/hw-events.c:92:3: warning: implicit declaration of function ‘memset’ [-Wimplicit-function-declaration]
   memset (&dummy, 0, sizeof dummy);
   ^~~~~~

../../../binutils-gdb/sim/lm32/../common/hw-handles.c: In function ‘hw_handle_remove_ihandle’:
../../../binutils-gdb/sim/lm32/../common/hw-handles.c:211:4: warning: implicit declaration of function ‘free’ [-Wimplicit-function-declaration]
    free (delete);
    ^~~~

../../../binutils-gdb/sim/lm32/../common/sim-fpu.c: In function ‘pack_fpu’:
../../../binutils-gdb/sim/lm32/../common/sim-fpu.c:292:7: warning: implicit declaration of function ‘abort’ [-Wimplicit-function-declaration]
       abort ();
       ^~~~~

sim/common/ChangeLog:

	* sim-options.c: Include "config.h".
	Include <stdio.h>.
	* sim-watch.c: Include "config.h".
	Include <stdio.h>.
	* hw-device.c: Include <string.h>.
	* hw-events.c: Include <string.h>.
	* hw-handles.c: Include <stdlib.h>.
	* sim-fpu.c: Include <stdlib.h>.