ARM: mv78xx0: simplify ethernet device creation

Out of the four ethernet devices on mv78xx0, only the first one
has an error interrupt line, for the other ones we pass NO_IRQ
and then ignore the argument.

In order to get closer to complete remove of NO_IRQ, this simply
drops the unused function arguments.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>