The green LED is not controlled by firmware so it should never blink. It is controlled by the battery charging IC. If it blinks then either the IC is defective (unlikely) or your USB charger can't supply the necessary 1A current. If this is the case, then your camera could be destroyed in no time. You should not use your camera in this state until you've found what's causing the green LED to blink.
Are you sure the green LED is actually blinking? I've never seen this. It's more likely that the green LED is on all the time, which is normal, but is being 'covered' by the brighter yellow LED.