net: e1000e: Remove unused declarations

Commit bdfe2da6 ("e1000e: cosmetic move of function prototypes to the new mac.h")
declared but never implemented them.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20230814135821.4808-1-yuehaibing@huawei.com


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