rockchip: phycore: Add ID page of M24C32-D EEPROM

The Identification Page (32 byte) is an additional page which can be written
and (later) permanently locked in Read-only mode.

phyCORE-RK3288 SoMs are using this page to describe the module variant.
This page also contains a MAC.

Our boards can be equipped with a different amount of EEPROMs. To make
this more transparent let's add an alias for the eeprom which stores the
module variant.

Signed-off-by: Wadim Egorov <w.egorov@phytec.de>
Acked-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>