i2c: Split smbus into parts

smbus.c and smbus.h had device side code, master side code, and
smbus.h has some smbus_eeprom.c definitions.  Split them into
separate files.

Signed-off-by: Corey Minyard <cminyard@mvista.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
18 files changed