bnx2x: Fix logic to get total no. of PFs per engine

Driver doesn't calculate total number of PFs configured on a
given engine correctly which messed up resources in the PFs
loaded on that engine, leading driver to exceed configuration
of resources (like vlan filters etc.) beyond the limit per
engine, which ended up with asserts from the firmware.

Signed-off-by: Manish Chopra <manishc@marvell.com>
Signed-off-by: Ariel Elior <aelior@marvell.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>