[U-Boot] suggest on how to convey value of 'CCSRBAR' to user on FSL PPC parts

[Kumar Gala]

I had two ideas on simple ways to convey the value of CCSRBAR, IMMR,  
etc.. on various Freescale PPC SoCs.  Knowing the value is useful in  
debugging if you need to dump the register space.  I wanted to see if  
people had a preference or other ideas:

1. add it as output when we boot:

U-Boot 2009.08-rc1-00030-g56bdfa9 (Jul 30 2009 - 10:52:13)

CPU:   8536E, Version: 1.1, (0x803f0091)
Core:  E500, Version: 3.0, (0x80210030)
..
CCSRBAR: 0xfe000000

2. add it as a environment variable

ccsrbar=fe000000

I also thought about having it as a command but that seems like a lot  
of code w/o any real purpose.

- k