davinci_emac: move arch-independent defines to separate header

DaVinci EMAC is found not only on DaVinci SoCs but on some OMAP3 SoCs
also. This patch moves common defines from arch-davinci/emac_defs.h to
drivers/net/davinci_emac.h

DaVinci specific PHY drivers hacked to include the new header. We might
want to switch to phylib in future.

Signed-off-by: Ilya Yanok <yanok@emcraft.com>
diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
index 36c33af..43c4373 100644
--- a/drivers/net/davinci_emac.c
+++ b/drivers/net/davinci_emac.c
@@ -43,6 +43,7 @@
 #include <malloc.h>
 #include <asm/arch/emac_defs.h>
 #include <asm/io.h>
+#include "davinci_emac.h"
 
 unsigned int	emac_dbg = 0;
 #define debug_emac(fmt,args...)	if (emac_dbg) printf(fmt,##args)