net: phy: Remove two unused function declarations

Commit 1e2dc145 ("net: ethtool: Add helpers for reporting test results")
declared but never implemented these function.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20230808144610.19096-1-yuehaibing@huawei.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>