Fix following warnings:
WARNING: struct file_operations should normally be const
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>
 /*
  *     Kernel interfaces
  */
-static struct file_operations hpwdt_fops = {
+static const struct file_operations hpwdt_fops = {
        .owner = THIS_MODULE,
        .llseek = no_llseek,
        .write = hpwdt_write,
 
        return 0;
 }
 
-static struct file_operations rc32434_wdt_fops = {
+static const struct file_operations rc32434_wdt_fops = {
        .owner          = THIS_MODULE,
        .llseek         = no_llseek,
        .write          = rc32434_wdt_write,