ppc4xx: Add output for bootrom location to 405EZ ports

Now 405EZ ports also show upon bootup from which boot device
they are configured to boot:

U-Boot 1.2.0-gd3832e8f-dirty (Apr 18 2007 - 07:47:05)

CPU:   AMCC PowerPC 405EZ Rev. A at 199.999 MHz (PLB=133, OPB=66, EBC=66 MHz)
       Bootstrap Option E - Boot ROM Location EBC (32 bits)
       16 kB I-Cache 16 kB D-Cache
Board: Acadia - AMCC PPC405EZ Evaluation Board

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