atmel_usba_udc: Fix endpoint names.

The endpoints of the atmel_usba_udc driver do not have directional
(in/out) or usage (ctrl/bulk/iso) restrictions, as their names
incorrectly implied.

Signed-off-by: Stelian Pop <stelian@popies.net>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>