net: stmmac: split the stmmac_adjust_link 10/100 case

The 10/100 case have too many ifcase.
This patch split it for removing an if.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Acked-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Reviewed-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -721,15 +721,19 @@ static void stmmac_adjust_link(struct net_device *dev)
 					ctrl &= ~priv->hw->link.port;
 				break;
 			case 100:
+				if (priv->plat->has_gmac ||
+				    priv->plat->has_gmac4) {
+					ctrl |= priv->hw->link.port;
+					ctrl |= priv->hw->link.speed;
+				} else {
+					ctrl &= ~priv->hw->link.port;
+				}
+				break;
 			case 10:
 				if (priv->plat->has_gmac ||
 				    priv->plat->has_gmac4) {
 					ctrl |= priv->hw->link.port;
-					if (phydev->speed == SPEED_100) {
-						ctrl |= priv->hw->link.speed;
-					} else {
-						ctrl &= ~(priv->hw->link.speed);
-					}
+					ctrl &= ~(priv->hw->link.speed);
 				} else {
 					ctrl &= ~priv->hw->link.port;
 				}