[POWERPC] 4xx: Add AMCC Haleakala (405EXr) dts

The patch adds the Haleakala dts. The Haleakala is a stripped down
version of the Kilauea (405EX) with only one EMAC and only one PCIe
interface.

Signed-off-by: Stefan Roese <sr@denx.de>
Signed-off-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>