- support NAND external boot
- enable only used clocks
- LCD fix in /env/bin/init
- I2C support
- SDCard support
- USB Host 1 support
- DFU support on OTG port
- update defconfig

Signed-off-by: Eric Bénard <eric@eukrea.com>

this will allow each arch to handle the boards more simply and depending on
there need

the env var BOARD will refer to the current board dirent

for sandbox as we have only one board the board dirent is arch/sandbox/board

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>