[NET] Kconfig: Rename MIKROTIK_RB500 -> MIKROTIK_RB532

The platform is actually named routerboard 532 so let's call it this.
Signed-off-by: NRalf Baechle <ralf@linux-mips.org>
Acked-by: NJeff Garzik <jeff@garzik.org>

drivers/net/Kconfig

@@ -469,7 +469,7 @@ config SNI_82596
 
 config KORINA
 	tristate "Korina (IDT RC32434) Ethernet support"
-	depends on NET_ETHERNET && MIKROTIK_RB500
+	depends on NET_ETHERNET && MIKROTIK_RB532
 	help
 	  If you have a Mikrotik RouterBoard 500 or IDT RC32434
 	  based system say Y. Otherwise say N.