staging: octeon-ethernet: allow to set IRQ smp_affinity freely

Currently the driver assumes that CPU 0 is handling all the hard IRQs.
This is wrong in Linux SMP systems where user is allowed to assign to
hardware IRQs to any CPU. The driver will stop working if user sets
smp_affinity so that interrupts end up being handled by other than CPU
0. The patch fixes that.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>