net: gmac_rockchip: Fix a register write in rk3328_gmac_set_to_rgmii

We have to use RK3328_RXCLK_DLY_ENA_GMAC_ENABLE instead of
RK3328_RXCLK_DLY_ENA_GMAC_MASK in rk3328_gmac_set_to_rgmii()
to enable the RX delay.
The MASK was used in a wrong way.

Signed-off-by: Janine Hagemann <j.hagemann@phytec.de>
Reviewed-by: Philipp Tomisch <philipp.tomisch@theobroma-systems.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/gmac_rockchip.c b/drivers/net/gmac_rockchip.c
index 30a24d1..0f91731 100644
--- a/drivers/net/gmac_rockchip.c
+++ b/drivers/net/gmac_rockchip.c
@@ -350,7 +350,7 @@
 		     RK3328_RXCLK_DLY_ENA_GMAC_MASK |
 		     RK3328_TXCLK_DLY_ENA_GMAC_MASK,
 		     RK3328_GMAC_PHY_INTF_SEL_RGMII |
-		     RK3328_RXCLK_DLY_ENA_GMAC_MASK |
+		     RK3328_RXCLK_DLY_ENA_GMAC_ENABLE |
 		     RK3328_TXCLK_DLY_ENA_GMAC_ENABLE);
 
 	rk_clrsetreg(&grf->mac_con[0],