arcnet: Convert printk to pr_<level>

Use the more current logging style.

Remove #define VERSION, use pr_info normally.
Add pr_fmt with "arcnet:" prefixes and KBUILD_MODNAME.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>