Add dev_delhandle() syscall to delete a device handle from process resources

kernel/syscall/dev.c

@@ -135,3 +135,21 @@ int32_t SYSCALL4(sys_dev_cmd, dev1, cmd1, argbuf1, len1) {
 done:
   return ret;
 }
+
+int32_t SYSCALL1(sys_dev_delhandle, dev1) {
+  uint64_t *devh = (uint64_t *)dev1;
+  int32_t ret = E_OK;
+
+  if (devh == NULL) {
+    return E_NOMEMORY;
+  }
+
+  spinlock_acquire(&PROCS.spinlock);
+  Proc *proc = NULL;
+  LL_FINDPROP(PROCS.procs, proc, pid, _caller_pid);
+  spinlock_release(&PROCS.spinlock);
+
+  proc->devs[*devh] = NULL;
+
+  return ret;
+}