cmd: eeprom: Staticize eeprom_i2c_bus

The eeprom_i2c_bus is not used outside of this file, make it static.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Heiko Schocher <hs@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
diff --git a/cmd/eeprom.c b/cmd/eeprom.c
index 667149e..792415e 100644
--- a/cmd/eeprom.c
+++ b/cmd/eeprom.c
@@ -61,7 +61,7 @@
 #endif
 
 #if defined(CONFIG_DM_I2C)
-int eeprom_i2c_bus;
+static int eeprom_i2c_bus;
 #endif
 
 __weak int eeprom_write_enable(unsigned dev_addr, int state)