net/bnxt: fix L2 context calculation for Thor

net/bnxt: fix L2 context calculation for Thor

On Wh+, number of L2 context supported by FW is the sum of number of
EM flow count and number of L2 context count returned in HWRM_FUNC_QCFG.
This is not true for Thor. Restrict this only for Whitney for now.

Fixes: ff9c0ca47e81 ("net/bnxt: save the number of EM flow count")
Cc: stable@dpdk.org
Signed-off-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>
Reviewed-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Lance Richardson <lance.richardson@broadcom.com>