net/bnxt: support TruFlow and AFM SRAM partitioning

net/bnxt: support TruFlow and AFM SRAM partitioning

Implement set/get_sram_policy which support both Rx/Tx
direction truflow type the specific SRAM bank.

Signed-off-by: Jay Ding <jay.ding@broadcom.com>
Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Reviewed-by: Randy Schacher <stuart.schacher@broadcom.com>
Reviewed-by: Farah Smith <farah.smith@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>