net: sxgbe: fix sparse warnings about static declaration

This fixes followings:

sparse warnings: (new ones prefixed by >>)

>> drivers/net/ethernet/samsung/sxgbe/sxgbe_platform.c:197:5:
sparse: symbol 'sxgbe_platform_freeze' was not declared. Should it be static?
>> drivers/net/ethernet/samsung/sxgbe/sxgbe_platform.c:204:5:
sparse: symbol 'sxgbe_platform_restore' was not declared. Should it be static?
>> drivers/net/ethernet/samsung/sxgbe/sxgbe_platform.c:228:24:
sparse: symbol 'sxgbe_platform_driver' was not declared. Should it be static?

>> drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c:1795:6:
sparse: symbol 'sxgbe_get_ops' was not declared. Should it be static?
Reported-by: Nkbuild test robot <fengguang.wu@intel.com>
Signed-off-by: NByungho An <bh74.an@samsung.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/samsung/sxgbe/sxgbe_main.c

@@ -2013,7 +2013,7 @@ static const struct net_device_ops sxgbe_netdev_ops = {
 };
 
 /* Get the hardware ops */
-void sxgbe_get_ops(struct sxgbe_ops * const ops_ptr)
+static void sxgbe_get_ops(struct sxgbe_ops * const ops_ptr)
 {
 	ops_ptr->mac		= sxgbe_get_core_ops();
 	ops_ptr->desc		= sxgbe_get_desc_ops();

drivers/net/ethernet/samsung/sxgbe/sxgbe_platform.c

@@ -200,14 +200,14 @@ static int sxgbe_platform_resume(struct device *dev)
 	return sxgbe_resume(ndev);
 }
 
-int sxgbe_platform_freeze(struct device *dev)
+static int sxgbe_platform_freeze(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 
 	return sxgbe_freeze(ndev);
 }
 
-int sxgbe_platform_restore(struct device *dev)
+static int sxgbe_platform_restore(struct device *dev)
 {
 	struct net_device *ndev = dev_get_drvdata(dev);
 
@@ -231,7 +231,7 @@ static const struct of_device_id sxgbe_dt_ids[] = {
 };
 MODULE_DEVICE_TABLE(of, sxgbe_dt_ids);
 
-struct platform_driver sxgbe_platform_driver = {
+static struct platform_driver sxgbe_platform_driver = {
 	.probe	= sxgbe_platform_probe,
 	.remove	= sxgbe_platform_remove,
 	.driver	= {