net: phy: mxl-86110: Add power management and soft reset support

Implement soft_reset, suspend, and resume callbacks using
genphy_soft_reset(), genphy_suspend(), and genphy_resume()
to fix PHY initialization and power management issues.

The soft_reset callback is needed to properly recover the PHY after an
ifconfig down/up cycle. Without it, the PHY can remain in power-down
state, causing MDIO register access failures during config_init().
The soft reset ensures the PHY is operational before configuration.

The suspend/resume callbacks enable proper power management during
system suspend/resume cycles.

Fixes: b2908a989c59 ("net: phy: add driver for MaxLinear MxL86110 PHY")
Signed-off-by: Stefano Radaelli <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

drivers/net/phy/mxl-86110.c

···
 		PHY_ID_MATCH_EXACT(PHY_ID_MXL86110),
 		.name			= "MXL86110 Gigabit Ethernet",
 		.config_init		= mxl86110_config_init,
+		.suspend		= genphy_suspend,
+		.resume			= genphy_resume,
+		.soft_reset		= genphy_soft_reset,
 		.get_wol		= mxl86110_get_wol,
 		.set_wol		= mxl86110_set_wol,
 		.led_brightness_set	= mxl86110_led_brightness_set,