net: hns3: Remove unused function declarations

net: hns3: Remove unused function declarations

Commit 1e6e76101fd9 ("net: hns3: configure promisc mode for VF asynchronously")
left behind hclge_inform_vf_promisc_info() declaration.
And commit 68c0a5c70614 ("net: hns3: Add HNS3 IMP(Integrated Mgmt Proc) Cmd Interface Support")
declared but never implemented hclge_cmd_mdio_write() and hclge_cmd_mdio_read().

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/20230803135138.37456-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>