soc/fsl/qbman: Use shared-dma-pool for BMan private memory allocations

Use the shared-memory-pool mechanism for free buffer proxy record
area allocation.

Signed-off-by: Roy Pledge <roy.pledge@nxp.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Li Yang <leoyang.li@nxp.com>