adi: Remove extern from function prototypes

There are a mix of function prototypes with and without extern
in the kernel sources.  Standardize on not using extern for
function prototypes.

Function prototypes don't need to be written with extern.
extern is assumed by the compiler.  Its use is as unnecessary as
using auto to declare automatic/local variables in a block.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/adi/bfin_mac.h

@@ -104,6 +104,6 @@ struct bfin_mac_local {
 #endif
 };
 
-extern int bfin_get_ether_addr(char *addr);
+int bfin_get_ether_addr(char *addr);
 
 #endif