compulab: eeprom: add support for defining eeprom i2c bus

Create CONFIG_SYS_I2C_EEPROM_BUS #define to tell the EEPROM
module what I2C bus the EEPROM is located at. Make cl_eeprom_read()
switch to that bus when reading EEPROM.

Cc: Igor Grinberg <grinberg@compulab.co.il>
Cc: Dmitry Lifshitz <lifshitz@compulab.co.il>
Cc: Tom Rini <trini@ti.com>
Cc: Marek Vasut <marex@denx.de>
Acked-by: Igor Grinberg <grinberg@compulab.co.il>
Acked-by: Dmitry Lifshitz <lifshitz@compulab.co.il>
Reviewed-by: Marek Vasut <marex@denx.de>
Signed-off-by: Nikita Kiryanov <nikita@compulab.co.il>
diff --git a/include/configs/cm_t335.h b/include/configs/cm_t335.h
index a3e6452..767ef3a 100644
--- a/include/configs/cm_t335.h
+++ b/include/configs/cm_t335.h
@@ -107,6 +107,7 @@
 /* I2C Configuration */
 #define CONFIG_SYS_I2C_EEPROM_ADDR	0x50	/* Main EEPROM */
 #define CONFIG_SYS_I2C_EEPROM_ADDR_LEN	1
+#define CONFIG_SYS_I2C_EEPROM_BUS	0
 
 /* SPL */
 #define CONFIG_SPL_LDSCRIPT		"$(CPUDIR)/am33xx/u-boot-spl.lds"