Merge branch 'ravb-add-mii-support-for-r-car-v4m'

Geert Uytterhoeven says:

====================
ravb: Add MII support for R-Car V4M

All EtherAVB instances on R-Car Gen3/Gen4 SoCs support the RGMII
interface.  In addition, the first two EtherAVB instances on R-Car V4M
also support the MII interface, but this is not yet supported by the
driver.  This patch series adds support for MII on R-Car Gen4, after the
customary cleanup.

The corresponding pin control support is available in [1].

Compile-tested only, as all AVB interfaces on the Gray Hawk Single
development board are connected to RGMII PHYs.
No regressions on R-Car V4H.

[1] "[PATCH/RFC] pinctrl: renesas: r8a779h0: Add AVB MII pins and groups"
    https://lore.kernel.org/4a0a12227f2145ef53b18bc08f45b19dcd745fc6.1718378739.git.geert+renesas@glider.be/

v1: https://lore.kernel.org/f0ef3e00aec461beb33869ab69ccb44a23d78f51.1718378166.git.geert+renesas@glider.be
====================

Link: https://patch.msgid.link/cover.1719234830.git.geert+renesas@glider.be
Signed-off-by: Jakub Kicinski <kuba@kernel.org>