net: dsa: lan9303: Move struct lan9303 to include/linux/dsa/lan9303.h

The next patch require net/dsa/tag_lan9303.c to access struct lan9303.
Therefore move struct lan9303 definitions from drivers/net/dsa/lan9303.h
to new file include/linux/dsa/lan9303.h.

Signed-off-by: Egil Hjelmeland <privat@egil-hjelmeland.no>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/MAINTAINERS b/MAINTAINERS
index e3a7ca9..c9ee7ab 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -9415,6 +9415,7 @@
 S:	Maintained
 F:	net/dsa/
 F:	include/net/dsa.h
+F:	include/linux/dsa/
 F:	drivers/net/dsa/
 
 NETWORKING [GENERAL]