keymile: Fix Coding style issues for keymile boards.

- use I/O accessors
  -> For accessing the FPGA therefore a struct km_bec_fpga
     is introduced.
- no longer externs needed
- to defines, that only select functions, don;t assign a
  numeric value
- Codingstyle changes to prevent checkpatch errors/warnings

Signed-off-by: Heiko Schocher <hs@denx.de>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
cc: Kim Phillips <kim.phillips@freescale.com>
cc: Holger Brunck <holger.brunck@keymile.com>
cc: Wolfgang Denk <wd@denx.de>
cc: Detlev Zundel <dzu@denx.de>
cc: Valentin Longchamp <valentin.longchamp@keymile.com>
cc: Prafulla Wadaskar <prafulla@marvell.com>