Merge branch 'net-phy-mdio-bcm-unimac-add-bcm6846-variant'

Linus Walleij says:

====================
net: phy: mdio-bcm-unimac: Add BCM6846 variant

As pointed out by Florian:
https://lore.kernel.org/linux-devicetree/b542b2e8-115c-4234-a464-e73aa6bece5c@broadcom.com/

The BCM6846 has a few extra registers and cannot reuse the
compatible string from other variants of the Unimac
MDIO block: we need to be able to tell them apart.
====================

Link: https://patch.msgid.link/20241012-bcm6846-mdio-v1-0-c703ca83e962@linaro.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>