NMI handler is now in mbed_overrides.c

libraries/mbed/targets/hal/TARGET_Freescale/TARGET_KSDK_MCUS/TARGET_K64F/gpio_irq_api.c

@@ -205,10 +205,3 @@ void gpio_irq_disable(gpio_irq_t *obj) {
     }
 }
 
-// Change the NMI pin to an input. This allows NMI pin to
-//  be used as a low power mode wakeup.  The application will
-//  need to change the pin back to NMI_b or wakeup only occurs once!
-void NMI_Handler(void) {
-    gpio_t gpio;
-    gpio_init_in(&gpio, PTA4);
-}