soc: fsl: qbman: replace CPU 0 with any online CPU in hotplug handlers

The existing code sets portal IRQ affinity to CPU 0 in the
offline hotplug handler. If CPU 0 is offline this is invalid.
Use a different online CPU instead.

Signed-off-by: Madalin Bucur <madalin.bucur@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>