MIPS: JZ4740: Export symbols to the watchdog driver module

  MODPOST 356 modules
ERROR: "jz4740_timer_disable_watchdog" [drivers/watchdog/jz4740_wdt.ko] undefine
d!
ERROR: "jz4740_timer_enable_watchdog" [drivers/watchdog/jz4740_wdt.ko] undefined
!
make[1]: *** [__modpost] Error 1

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>