i2c: Cleanups to the i2c-nforce2 bus driver

Summary of changes:

- fixes:
   o legacy I/O region size is 64 bytes, not 8 bytes
- general cleanup:
   o removed code for the unsupported I2C block data, block data,
      proc call and block proc call transfer modes
   o removed detail warnings about unsupported modes that are
     covered in a general warning (unsupported transaction...)
     anyway
   o removed necessity of a definition of struct i2c_adapter
   o moved definition of struct i2c_algorithm, making forward
     declarations of nforce2_access and nforce2_func unnecessary
- minor changes:
   o in the description mention the nForce 5xx chipsets
   o changes my e-mail address in MODULE_AUTHOR

Theses cleanups shrink the driver binary size from 4.0 kB to 2.7 kB
on i386.

Signed-off-by: Hans-Frieder Vogt <hfvogt@gmx.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>