keymile, common: add setting of some environment variables

keymile, common: add setting of some environment variables

This patch adds last_stage_init to all keymile boards. And
in the last stage init some environment variables for u-boot
were set. Currently these are pnvramaddr, pram and var address.

Signed-off-by: Holger Brunck <[email protected]>
Signed-off-by: Heiko Schocher <[email protected]>
Acked-by: Kim Phillips <[email protected]>
cc: Valentin Longchamp <[email protected]>
cc: Wolfgang Denk <[email protected]>
cc: Kim Phillips <[email protected]>