Merge patch series "am65-cpsw-nuss phy_interface_t fixup for fixed TX delay"

Matthias Schiffer <matthias.schiffer@ew.tq-group.com> says:

Following a discussion on the LKML [1], there has been a clarification
of the correct use of the rgmii(/-rxid/-txid/-it) phy-modes [2] - namely,
that they don't describe the interface at the MAC or PHY boundary, but
whether the PCB traces add delays or not (where it is
implementation-defined whether the delays are added on the MAC or PHY
side in the latter case).

Accordingly, a fixup has been implemented in the am65-cpsw-nuss driver
to make it follow the clarified rules [3]; apply the same change to
U-Boot. Backwards compatibility is preserved: using an old DTB with
the wrong phy-mode only results in a warning message, but keeps the
Ethernet working. With a new DTB from Linux 6.17+ that sets the mode to
rgmii-id, these changes are necessary to avoid using an unsupported/
reserved configuration. See the commit message of patch 2/2 for some
additional detail.

[1] https://lore.kernel.org/lkml/d25b1447-c28b-4998-b238-92672434dc28@lunn.ch/
[2] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c360eb0c3ccb95306704fd221442283ee82f1f58
[3] https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ca13b249f291f4920466638d1adbfb3f9c8db6e9

Link: https://lore.kernel.org/r/cover.1759218200.git.matthias.schiffer@ew.tq-group.com