MIPS: Alchemy: Extended DB1200 board support.

Create own directory for DB1200 code and update it with new features.

- SPI support:
  - tmp121 temperature sensor
  - SPI flash on DB1200
- I2C support
  - NE1619 sensor
  - AT24 eeprom
- I2C/SPI can be selected at boot time via switch S6.8
- Carddetect IRQs for SD cards.
- gen_nand based NAND support.
- hexleds count sleep/wake transitions.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Cc: Linux-MIPS <linux-mips@linux-mips.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>