shared: split out ioprio related stuff into ioprio-util.[ch]

No actual code changes, just some splitting out.

src/basic/process-util.c

@@ -1132,23 +1132,6 @@ int pid_compare_func(const pid_t *a, const pid_t *b) {
         return CMP(*a, *b);
 }
 
-int ioprio_parse_priority(const char *s, int *ret) {
-        int i, r;
-
-        assert(s);
-        assert(ret);
-
-        r = safe_atoi(s, &i);
-        if (r < 0)
-                return r;
-
-        if (!ioprio_priority_is_valid(i))
-                return -EINVAL;
-
-        *ret = i;
-        return 0;
-}
-
 /* The cached PID, possible values:
  *
  *     == UNSET [0]  → cache not initialized yet
@@ -1627,14 +1610,6 @@ _noreturn_ void freeze(void) {
                 pause();
 }
 
-static const char *const ioprio_class_table[] = {
-        [IOPRIO_CLASS_NONE] = "none",
-        [IOPRIO_CLASS_RT] = "realtime",
-        [IOPRIO_CLASS_BE] = "best-effort",
-        [IOPRIO_CLASS_IDLE] = "idle",
-};
-
-DEFINE_STRING_TABLE_LOOKUP_WITH_FALLBACK(ioprio_class, int, IOPRIO_N_CLASSES);
 
 static const char *const sigchld_code_table[] = {
         [CLD_EXITED] = "exited",