net: macmace: Allow modular build

Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/apple/Kconfig

@@ -51,7 +51,7 @@ config BMAC
 	  will be called bmac.
 
 config MACMACE
-	bool "Macintosh (AV) onboard MACE ethernet"
+	tristate "Macintosh (AV) onboard MACE ethernet"
 	depends on MAC
 	select CRC32
 	---help---