In BF60x processor, Watchdog generates only GP interrupt upon expiry. You have two options to do the reset using the watchdog
(a) In the GP interrupt ISR, set bit 0 of RCU_CTL register to reset the processor. This resets all the system units and reboots.
(b) Declare the interrupt coming from Watchdog as “FAULT” in the SEC and this can reset the processor.