ppc4xx: Add initial AMCC Haleakala PPC405EXr eval board support

The Haleakala is nearly identical with the Kilauea eval board. The only
difference is that the 405EXr only supports one EMAC and one PCIe
interface. This patch adds support for the Haleakala board by using
the identical image for Kilauea and Haleakala. The distinction is done
by comparing the PVR.

Signed-off-by: Stefan Roese <sr@denx.de>