i2c, ppc4xx: fix compiling KAREF and METROBOX boards.

i2c, ppc4xx: fix compiling KAREF and METROBOX boards.

commit eb5eb2b0f744f0cba405160c5d01335c40f09acf

ppc4xx: Cleanup PPC4xx I2C infrastructure

This patch cleans up the PPC4xx I2C intrastructure:

- Use C struct to describe the I2C registers instead of defines
- Coding style cleanup (braces, whitespace, comments, line length)
- Extract common code from i2c_read() and i2c_write()
- Remove unneeded IIC defines from ppc405.h & ppc440.h

breaks comiling for the KAREF and METROBOX boards.

This patch fixes this issue.

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