bnxt_en: New Broadcom ethernet driver.

Broadcom ethernet driver for the new family of NetXtreme-C/E
ethernet devices.

v5:
  - Removed empty blank lines at end of files (noted by David Miller).
  - Moved busy poll helper functions to bnxt.h to at least make the
    .c file look less cluttered with #ifdef (noted by Stephen Hemminger).

v4:
  - Broke up 2 long message strings with "\n" (suggested by John Linville)
  - Constify an array of strings (suggested by Stephen Hemminger)
  - Improve bnxt_vf_pciid() (suggested by Stephen Hemminger)
  - Use PCI_VDEVICE() to populate pci_device_id table for more compact
    source.

v3:
  - Fixed 2 more sparse warnings.
  - Removed some unused structures in .h files.

v2:
  - Fixed all kbuild test robot reported warnings.
  - Fixed many of the checkpatch.pl errors and warnings.
  - Fixed the Kconfig description (noted by Dmitry Kravkov).

Acked-by: Eddie Wai <eddie.wai@broadcom.com>
Acked-by: Jeffrey Huang <huangjw@broadcom.com>
Signed-off-by: Prashant Sreedharan <prashant@broadcom.com>
Signed-off-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>