net: phy: realtek: create rtl8211f_config_rgmii_delay()

net: phy: realtek: create rtl8211f_config_rgmii_delay()

The control flow in rtl8211f_config_init() has some pitfalls which were
probably unintended. Specifically it has an early return:

	switch (phydev->interface) {
	...
	default: /* the rest of the modes imply leaving delay as is. */
		return 0;
	}

which exits the entire config_init() function. This means it also skips
doing things such as disabling CLKOUT or disabling PHY-mode EEE.

For the RTL8211FS, which uses PHY_INTERFACE_MODE_SGMII, this might be a
problem. However, I don't know that it is, so there is no Fixes: tag.
The issue was observed through code inspection.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20251117234033.345679-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>