travis.yml: some adaptions

- adapt to build with eldk-5.4
- add more targets for building with buildman:
  - freescale -x arm,m68k,aarch64
  - arm1136
  - arm1176
  - arm720t
  - arm920t
  - davinci
  - kirkwood

Signed-off-by: Heiko Schocher <hs@denx.de>
Reviewed-by: Roger Meier <r.meier@siemens.com>