net: stmmac: platform: fix build warning when with !CONFIG_PM_SLEEP

stable inclusion
from stable-v5.10.83
commit 98b02755d544ce26ac0a41ff52bf56f2bd79e4c0
bugzilla: 185879 https://gitee.com/openeuler/kernel/issues/I4QUVG

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=98b02755d544ce26ac0a41ff52bf56f2bd79e4c0

--------------------------------

commit 2a48d96f upstream.

Use __maybe_unused for noirq_suspend()/noirq_resume() hooks to avoid
build warning with !CONFIG_PM_SLEEP:

>> drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:796:12: error: 'stmmac_pltfr_noirq_resume' defined but not used [-Werror=unused-function]
     796 | static int stmmac_pltfr_noirq_resume(struct device *dev)
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~
>> drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c:775:12: error: 'stmmac_pltfr_noirq_suspend' defined but not used [-Werror=unused-function]
     775 | static int stmmac_pltfr_noirq_suspend(struct device *dev)
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~
   cc1: all warnings being treated as errors

Fixes: 276aae37 ("net: stmmac: fix system hang caused by eee_ctrl_timer during suspend/resume")
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NJoakim Zhang <qiangqing.zhang@nxp.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

@@ -779,7 +779,7 @@ static int __maybe_unused stmmac_runtime_resume(struct device *dev)
 	return stmmac_bus_clks_config(priv, true);
 }
 
-static int stmmac_pltfr_noirq_suspend(struct device *dev)
+static int __maybe_unused stmmac_pltfr_noirq_suspend(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct stmmac_priv *priv = netdev_priv(ndev);
@@ -800,7 +800,7 @@ static int stmmac_pltfr_noirq_suspend(struct device *dev)
 	return 0;
 }
 
-static int stmmac_pltfr_noirq_resume(struct device *dev)
+static int __maybe_unused stmmac_pltfr_noirq_resume(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 	struct stmmac_priv *priv = netdev_priv(ndev);