bus: mc-bus: Add support for mapping shareable portals

Starting with v5 of NXP QBMan devices the hardware supports using
regular cacheable/shareable memory as the backing store for the
portals.

This patch adds support for the new portal mode by switching to
use the DPRC get object region v2 command which returns both
a base address and offset for the portal memory. The new portal
region is identified as shareable through the addition of a new
flag.

Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
Reviewed-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>