configs: NOP_USB_XCEIV=y and USB_GADGET=y

As of 5.13, "suppliers" (kinds of dependencies such as power and
PHY drivers) are checked by the driver framework rather than the
driver, making declaring such a supplier for a device without having
a driver available effectively fatal even if the "consumer" driver
makes no reference to it. The generic USB PHY declared for the DWC
USB block is such a supplier, but the Pi 1-3 defconfigs don't include
the generic PHY driver, making USB on those Pis unusable.

Add USB generic PHY support to the remaining Pi defconfigs, which for
Kconfig reasons also requires gadget support to be built-in (the kernel
size increase appears to be minimal).

See: https://github.com/raspberrypi/linux/issues/4496

Signed-off-by: Phil Elwell <phil@raspberrypi.com>