driver: usb_dc_sam_usbhs: Initialize Endpoint FIFO
driver: usb_dc_sam_usbhs: Initialize Endpoint FIFO

Ensure that the FIFO of each endpoint is initialized during endpoint
configuration, to prevent a NULL FIFO from being encountered during the
first call to usb_dc_ep_write() for a given endpoint.

Signed-off-by: Nick Kraus <75ef9faee755c70589550b513ad881e5a603182c@nckraus.com>

galak/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr