net: phy: phy_device: Fix PHY LED blinking code comment

Fix copy-paste error in the code comment. The code refers to
LED blinking configuration, not brightness configuration. It
was likely copied from comment above this one which does
refer to brightness configuration.

Fixes: 4e90101 ("net: phy: phy_device: Call into the PHY driver to set LED blinking")
Signed-off-by: Marek Vasut <marex@denx.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20240626030638.512069-1-marex@denx.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Marek Vasut

include/linux/phy.h

@@ -1122,7 +1122,7 @@ struct phy_driver {
 				  u8 index, enum led_brightness value);
 
 	/**
-	 * @led_blink_set: Set a PHY LED brightness.  Index indicates
+	 * @led_blink_set: Set a PHY LED blinking.  Index indicates
 	 * which of the PHYs led should be configured to blink. Delays
 	 * are in milliseconds and if both are zero then a sensible
 	 * default should be chosen.  The call should adjust the