cmd: eeprom: Do not rewrite EEPROM I2C bus with DM I2C enabled

With DM I2C, the EEPROM bus has been correctly configured in
eeprom_execute_command() already. Do not reconfigure it here
with hard-coded bus number again.

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>