net/bnxt: add SRAM manager model

net/bnxt: add SRAM manager model

The SRAM manager supports allocation and free of variable sized
records within SRAM memory.  These record sizes are 8, 16, 32, or
64B. The SRAM manager algorithm will not fragment memory during
run time. Previous implementation only included fixed size 64B
records regardless of the size required.

Signed-off-by: Farah Smith <farah.smith@broadcom.com>
Reviewed-by: Shahaji Bhosle <sbhosle@broadcom.com>
Reviewed-by: Peter Spreadborough <peter.spreadborough@broadcom.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>