Convert CONFIG_ARP_TIMEOUT to Kconfig

This converts the following to Kconfig:
   CONFIG_ARP_TIMEOUT

Cc: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/mvebu_puzzle-m801-88f8040_defconfig b/configs/mvebu_puzzle-m801-88f8040_defconfig
index af01e61..b16a933 100644
--- a/configs/mvebu_puzzle-m801-88f8040_defconfig
+++ b/configs/mvebu_puzzle-m801-88f8040_defconfig
@@ -44,6 +44,7 @@
 CONFIG_MAC_PARTITION=y
 CONFIG_ENV_IS_IN_SPI_FLASH=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_ARP_TIMEOUT=200
 CONFIG_NET_RANDOM_ETHADDR=y
 CONFIG_AHCI_MVEBU=y
 CONFIG_DM_PCA953X=y