eeprom: at25: Add example part numbers

To save the interested reader some time, add examples of AT25 part
numbers that correspond to EEPROMs rather than flashes.

Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Link: https://lore.kernel.org/r/20201107133337.1066271-1-j.neuschaefer@gmx.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>