Add support for AMCC Sequoia PPC440EPx eval board

- Add support for PPC440EPx & PPC440GRx
- Add support for PPC440EP(x)/GR(x) NAND controller
  in cpu/ppc4xx directory
- Add NAND boot functionality for Sequoia board,
  please see doc/README.nand-boot-ppc440 for details
- This Sequoia NAND image doesn't support environment
  in NAND for now. This will be added in a short while.
Patch by Stefan Roese, 07 Sep 2006

dtt/lm75.c

@@ -146,8 +146,13 @@ static int _dtt_init(int sensor)
     /*
      * Setup configuraton register
      */
+#ifdef CONFIG_DTT_AD7414
+    /* config = alert active low and disabled */
+    val = 0x60;
+#else
     /* config = 6 sample integration, int mode, active low, and enable */
     val = 0x18;
+#endif
     if (dtt_write(sensor, DTT_CONFIG, val) != 0)
 	return 1;