Convert the IDT 89HPESx device binding to DT schema format.

"onsemi,24c64" was not a documented compatible string, so update the
example to "atmel,24c64". It's not clear what's in use here as no
upstream dts files have the eeprom child node.
Acked-by: Serge Semin <fancer.lancer@gmail.com>
Link: https://lore.kernel.org/r/20221005212631.122145-1-robh@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>