bnxt_en: Set up the chip specific RSS table size.

Currently, we allocate one page for the hardware DMA RSS indirection
table.  While the size is currently big enough for all chips, future
chip variations may support bigger sizes, so it is better to calculate
and store the chip specific size and allocate accordingly.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>