net: bcmgenet: restore PHY power management flags

Restore PHY_BRCM_AUTO_PWRDWN_ENABLE, PHY_BRCM_DIS_TXCRXC_NOENRGY and
PHY_BRCM_IDDQ_SUSPEND in bcmgenet_mii_probe(), reverting the
downstream hunk that snuck into 7dd290a ("xhci: add quirk...")
back in March 2022.

That hunk worked around raspberrypi/rpi-eeprom#417: on Pi 4B rev 1.1
only, the bootloader couldn't recover the PHY from IDDQ-SR after a
kernel reboot. CM4 and newer Pi 4B revs were never affected. The
rpi-eeprom fix shipped in April 2022 (release c68f0c06) and the issue
was closed a month later.

With the bootloader fix ~4 years deployed, drop the kernel-side
workaround and get back the "several hundreds of milliwatts" of idle
power savings Florian quoted in the issue thread.

Signed-off-by: Nicolai Buchwitz <nb@tipi-net.de>

Author: nbuchwitz

drivers/net/ethernet/broadcom/genet/bcmmii.c

@@ -306,7 +306,9 @@ int bcmgenet_mii_probe(struct net_device *dev)
 	struct device_node *dn = kdev->of_node;
 	phy_interface_t phy_iface = priv->phy_interface;
 	struct phy_device *phydev;
-	u32 phy_flags = 0;
+	u32 phy_flags = PHY_BRCM_AUTO_PWRDWN_ENABLE |
+			PHY_BRCM_DIS_TXCRXC_NOENRGY |
+			PHY_BRCM_IDDQ_SUSPEND;
 	int ret;
 
 	/* Communicate the integrated PHY revision */