Convert CONFIG_SYS_BARGSIZE to Kconfig

This converts the following to Kconfig:
   CONFIG_SYS_BARGSIZE

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/configs/imx8mn_venice.h b/include/configs/imx8mn_venice.h
index 538b23a..4641996 100644
--- a/include/configs/imx8mn_venice.h
+++ b/include/configs/imx8mn_venice.h
@@ -100,6 +100,8 @@
 /* UART */
 #define CONFIG_MXC_UART_BASE		UART_BASE_ADDR(2)
 
-#define CONFIG_SYS_BARGSIZE		CONFIG_SYS_CBSIZE
+/* FEC */
+#define CONFIG_FEC_MXC_PHYADDR          0
+#define FEC_QUIRK_ENET_MAC
 
 #endif