net: ethernet: ti/cpsw-common.c: fix sparse warning

this patch fixes following sparse warning:

cpsw-common.c:23:5: warning: symbol 'cpsw_am33xx_cm_get_macid' was not declared. Should it be static?
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/ti/cpsw-common.c

@@ -17,6 +17,8 @@
 #include <linux/regmap.h>
 #include <linux/mfd/syscon.h>
 
+#include "cpsw.h"
+
 #define AM33XX_CTRL_MAC_LO_REG(offset, id) ((offset) + 0x8 * (id))
 #define AM33XX_CTRL_MAC_HI_REG(offset, id) ((offset) + 0x8 * (id) + 0x4)