usb: dwc3: gadget: Avoid spuriously printing NO_PULLUP in log

This log message can come unnecessarily particularly when the
controller is operating in host mode and the xHCI HCD driver
is primarily handling interrupts. As there should be no gadget
specific events there should not be any value showing in the
GEVNTCOUNT registers so dwc3_interrupt() should normally return
silently. Only print the "NO_PULLUP" log in case there are
new/pending events and the gadget is in halted state.

Change-Id: I4e5040409a14f18d454833fd67d41ca5d0f13501
Signed-off-by: Jack Pham <jackp@codeaurora.org>