[U-Boot] compulab trimslice build error due to 52658fda7abc ("compulab: eeprom: add support for defining eeprom i2c bus")

[Stephen Warren]

After commit 52658fda7abc ("compulab: eeprom: add support for defining 
eeprom i2c bus"), the trimslice board fails to build with:

.../board/compulab/common/eeprom.c: In function ‘cl_eeprom_read’:
.../board/compulab/common/eeprom.c:37:24: error: 
‘CONFIG_SYS_I2C_EEPROM_BUS’ undeclared (first use in this function)
.../board/compulab/common/eeprom.c:37:24: note: each undeclared 
identifier is reported only once for each function it appears in

I have no idea if this EEPROM code should even run on TrimSlice or not. 
Can you take a look at the correct fix?