net: pcnet: Add Kconfig entries

Add Kconfig entries for the pcnet driver and convert MIPS malta
to use those.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
Cc: Joe Hershberger <joe.hershberger@ni.com>
diff --git a/drivers/net/Kconfig b/drivers/net/Kconfig
index ed07a78..1566b3b 100644
--- a/drivers/net/Kconfig
+++ b/drivers/net/Kconfig
@@ -398,6 +398,12 @@
 	help
 	  Enable support of the Media-Independent Interface (MII)
 
+config PCNET
+	bool "AMD PCnet series Ethernet controller driver"
+	help
+	  This driver supports AMD PCnet series fast ethernet family of
+	  PCI chipsets/adapters.
+
 config RTL8139
 	bool "Realtek 8139 series Ethernet controller driver"
 	help