arm64: dts: renesas: Drop KSZ9131 PHY C22 compatible strings

arm64: dts: renesas: Drop KSZ9131 PHY C22 compatible strings

The Microchip KSZ9131 PHY schema indicates that the compatible string
"ethernet-phy-id0022.1640" must not be followed by any other compatible
string.  Drop trailing "ethernet-phy-ieee802.3-c22" to match the schema.

Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260313164008.40933-4-marek.vasut+renesas@mailbox.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>