drivers: eeprom: mark the EEPROM API as stable

Mark the EEPROM API as stable for the upcoming Zephyr v2.5.0. The EEPROM
API was introduced in Zephyr v2.1.0 and has not seen any changes since.

Signed-off-by: Henrik Brix Andersen <[email protected]>

Author: henrikbrixandersen

doc/reference/overview.rst

@@ -98,7 +98,7 @@ current :ref:`stability level <api_lifecycle>`.
      - 2.4
 
    * - :ref:`eeprom_api`
-     - Unstable
+     - Stable
      - 2.1
      - 2.1