bus/dpaa: decouple FQ portal alloc and init

bus/dpaa: decouple FQ portal alloc and init

The decoupling of FQ portal allocation is required as a
pre-requisite to support Rx interrupts as we need to have
event FD's at portal allocation i.e. before the
initialization of the Frame Queues.
This change will help us get the event fd once the portals
have been allocated for static FQ's.

Signed-off-by: Nipun Gupta <nipun.gupta@nxp.com>
Acked-by: Hemant Agrawal <hemant.agrawal@nxp.com>