Cleanups to the i2c-viapro driver:
* Kill unused defines.
* Kill interrupt-related code, as the driver doesn't use interrupts.
* Fix broken comments (some copied from i2c-piix4.)
* Centralize the unsupported command error case in vt596_access.
That way we'll catch all unsupported commands, not only
I2C_SMBUS_PROC_CALL.
* Refactor some code.
* Convert some dev_dbg into dev_err. Errors better be reported even in
non-debug mode.
* Do not verify that the final reset succeeded. It'll be checked at
the beginning of the next transaction anyway.
* Use the driver name to reserve the I/O region.
* Do not print the contents of the SMBREV register, it reads 0 on all
chips I've seen so far.
* Some other minor fixes all over the place.