eeprom: at25: make FRAM device ID error message more precise

The error description would be wrong in case the "size" Devicetree
property is missing for an FRAM without device ID.

Signed-off-by: Markus Heidelberg <m.heidelberg@cab.de>
Reviewed-by: Alexander Sverdlin <alexander.sverdlin@gmail.com>
Link: https://lore.kernel.org/r/20250815095839.4219-4-m.heidelberg@cab.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>