ARM: dts: BCM53573: Fix Ethernet info for Luxul devices

ARM: dts: BCM53573: Fix Ethernet info for Luxul devices

[ Upstream commit 44ad8207806973f4e4f7d870fff36cc01f494250 ]

Both Luxul's XAP devices (XAP-810 and XAP-1440) are access points that
use a non-default design. They don't include switch but have a single
Ethernet port and BCM54210E PHY connected to the Ethernet controller's
MDIO bus.

Support for those devices regressed due to two changes:

1. Describing MDIO bus with switch
After commit 9fb90ae6cae7 ("ARM: dts: BCM53573: Describe on-SoC BCM53125
rev 4 switch") Linux stopped probing for MDIO devices.

2. Dropping hardcoded BCM54210E delays
In commit fea7fda7f50a ("net: phy: broadcom: Fix RGMII delays
configuration for BCM54210E") support for other PHY modes was added but
that requires a proper "phy-mode" value in DT.

Both above changes are correct (they don't need to be reverted or
anything) but they need this fix for DT data to be correct and for Linux
to work properly.

Fixes: 9fb90ae6cae7 ("ARM: dts: BCM53573: Describe on-SoC BCM53125 rev 4 switch")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Link: https://lore.kernel.org/r/20230713111145.14864-1-zajec5@gmail.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>