drivers: net: cpsw: Fix TX_IN_SEL offset

The TX_IN_SEL offset for the CPSW_PORT/TX_IN_CTL register was
incorrect. This caused the Dual MAC mode to never get set when
it should. It also caused possible unintentional setting of a
bit in the CPSW_PORT/TX_BLKS_REM register.

The purpose of setting the Dual MAC mode for this register is to:

    "... allow packets from both ethernet ports to be written into
     the FIFO without one port starving the other port."
					- AM335x ARM TRM

Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reviewed-by: Mugunthan V N <mugunthanvnm@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw.c

@@ -129,9 +129,9 @@ do {								\
 #define CPSW_VLAN_AWARE		BIT(1)
 #define CPSW_ALE_VLAN_AWARE	1
 
-#define CPSW_FIFO_NORMAL_MODE		(0 << 15)
-#define CPSW_FIFO_DUAL_MAC_MODE		(1 << 15)
-#define CPSW_FIFO_RATE_LIMIT_MODE	(2 << 15)
+#define CPSW_FIFO_NORMAL_MODE		(0 << 16)
+#define CPSW_FIFO_DUAL_MAC_MODE		(1 << 16)
+#define CPSW_FIFO_RATE_LIMIT_MODE	(2 << 16)
 
 #define CPSW_INTPACEEN		(0x3f << 16)
 #define CPSW_INTPRESCALE_MASK	(0x7FF << 0)