bnxt_en: Add cache line size setting to optimize performance.

bnxt_en: Add cache line size setting to optimize performance.

Orabug: 27648355, 27648339

The chip supports 64-byte and 128-byte cache line size for more optimal
DMA performance when matched to the CPU cache line size.  The default is 64.
If the system is using 128-byte cache line size, set it to 128.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit c3480a603773cfc5d8aa44dbbee6c96e0f9d4d9d)
Signed-off-by: Brian Maly <brian.maly@oracle.com>
Reviewed-by: Jack Vogel <jack.vogel@oracle.com>
Conflicts:
	drivers/net/ethernet/broadcom/bnxt/bnxt.c