doc: migration: 4.2: mention ethernet change

mention change of ethernet spped enums.

Signed-off-by: Fin Maaß <[email protected]>

Author: maass-hamburg

doc/releases/migration-guide-4.2.rst

@@ -77,6 +77,20 @@ Ethernet
   kconfig options: :kconfig:option:`CONFIG_ETH_NATIVE_POSIX` and its related options have been
   deprecated in favor of :kconfig:option:`CONFIG_ETH_NATIVE_TAP` (:github:`86578`).
 
+* Enums for the Ethernet speed have been renamed to be more indepedent of the used medium.
+  ``LINK_HALF_10BASE_T``, ``LINK_FULL_10BASE_T``, ``LINK_HALF_100BASE_T``, ``LINK_FULL_100BASE_T``,
+  ``LINK_HALF_1000BASE_T``, ``LINK_FULL_1000BASE_T``, ``LINK_FULL_2500BASE_T`` and
+  ``LINK_FULL_5000BASE_T`` have been renamed to :c:enumerator:`LINK_HALF_10BASE`,
+  :c:enumerator:`LINK_FULL_10BASE`, :c:enumerator:`LINK_HALF_100BASE`,
+  :c:enumerator:`LINK_FULL_100BASE`, :c:enumerator:`LINK_HALF_1000BASE`,
+  :c:enumerator:`LINK_FULL_1000BASE`, :c:enumerator:`LINK_FULL_2500BASE` and
+  :c:enumerator:`LINK_FULL_5000BASE`.
+  ``ETHERNET_LINK_10BASE_T``, ``ETHERNET_LINK_100BASE_T``, ``ETHERNET_LINK_1000BASE_T``,
+  ``ETHERNET_LINK_2500BASE_T`` and ``ETHERNET_LINK_5000BASE_T`` have been renamed to
+  :c:enumerator:`ETHERNET_LINK_10BASE`, :c:enumerator:`ETHERNET_LINK_100BASE`,
+  :c:enumerator:`ETHERNET_LINK_1000BASE`, :c:enumerator:`ETHERNET_LINK_2500BASE` and
+  :c:enumerator:`ETHERNET_LINK_5000BASE` respectively.
+
 
 GPIO
 ====