net: phy: aquantia: add missing include guards

The header is missing the include guards so add them.
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Fixes: fb470f70 ("net: phy: aquantia: add hwmon support")
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Link: https://patch.msgid.link/20240701080322.9569-1-brgl@bgdev.plSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/phy/aquantia/aquantia.h

@@ -6,6 +6,9 @@
  * Author: Heiner Kallweit <hkallweit1@gmail.com>
  */
 
+#ifndef AQUANTIA_H
+#define AQUANTIA_H
+
 #include <linux/device.h>
 #include <linux/phy.h>
 
@@ -120,3 +123,5 @@ static inline int aqr_hwmon_probe(struct phy_device *phydev) { return 0; }
 #endif
 
 int aqr_firmware_load(struct phy_device *phydev);
+
+#endif /* AQUANTIA_H */