arm, at91: add axm extensions

add extensions for the axm board:
- power on LED on power up
- press both recovery buttons on power up to enter
  recovery mode
- detect 64 MiB and 128 MiB ramsize
- PHY rest at reboot because of ATMEL bug
- use siemens update concept
- add axm default environment
- set CONFIG_SPL_MAX_SIZE to 15k

Signed-off-by: Heiko Schocher <hs@denx.de>
2 files changed