sim: drop unused targ-vals.h includes

This is used in a few places where it's not needed.  Drop the include
to avoid the build-time generated header file as we move to drop it.

sim/common/sim-io.c

@@ -25,7 +25,6 @@
 #include "sim-main.h"
 #include "sim-io.h"
 #include "sim/callback.h"
-#include "targ-vals.h"
 
 #include <errno.h>
 #if HAVE_FCNTL_H

sim/common/sim-syscall.c

@@ -25,7 +25,6 @@
 #include "sim-main.h"
 #include "sim-syscall.h"
 #include "sim/callback.h"
-#include "targ-vals.h"
 
 /* Read/write functions for system call interface.  */
 

sim/common/syscall.c

@@ -41,7 +41,6 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include "sim/callback.h"
-#include "targ-vals.h"
 
 #ifndef ENOSYS
 #define ENOSYS EINVAL

sim/m32r/traps.c

@@ -26,7 +26,6 @@
 #include "sim-syscall.h"
 #include "sim/callback.h"
 #include "syscall.h"
-#include "targ-vals.h"
 #include <dirent.h>
 #include <errno.h>
 #include <fcntl.h>

sim/msp430/msp430-sim.c

@@ -32,7 +32,6 @@
 #include "sim-main.h"
 #include "sim-signal.h"
 #include "sim-syscall.h"
-#include "targ-vals.h"
 
 static sim_cia
 msp430_pc_fetch (SIM_CPU *cpu)

sim/riscv/sim-main.c

@@ -34,8 +34,6 @@
 #include "opcode/riscv.h"
 
 #include "gdb/sim-riscv.h"
-
-#include "targ-vals.h"
 
 #define TRACE_REG(cpu, reg) \
   TRACE_REGISTER (cpu, "wrote %s = %#" PRIxTW, riscv_gpr_names_abi[reg], \