efi_loader: implement SetWatchdogTimer

The watchdog is initialized with a 5 minute timeout period.
It can be reset by SetWatchdogTimer.
It is stopped by ExitBoottimeServices.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>

cmd/bootefi.c

@@ -43,6 +43,7 @@ static void efi_init_obj_list(void)
 #ifdef CONFIG_GENERATE_SMBIOS_TABLE
 	efi_smbios_register();
 #endif
+	efi_watchdog_register();
 
 	/* Initialize EFI runtime services */
 	efi_reset_system_init();