Pull out the code computing the EEPROM address into separate function
so that it's not duplicated.
Signed-off-by: NMarek Vasut <marex@denx.de>
Cc: Simon Glass <sjg@chromium.org>
Cc: Tom Rini <trini@konsulko.com>
Cc: Heiko Schocher <hs@denx.de>
Reviewed-by: NHeiko Schocher <hs@denx.de>