soc: fsl: bman_portals: defer probe after bman's probe

A crash in bman portal probing could not be triggered (as is the case
with qman portals) but it does make calls [1] into the bman driver so
lets make sure the bman portal probing happens after bman's.

[1]  bman_p_irqsource_add() (in bman) called by:
       init_pcfg() called by:
         bman_portal_probe()

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>