Convert CONFIG_NET_RETRY_COUNT to Kconfig

This converts the following to Kconfig:
   CONFIG_NET_RETRY_COUNT

Cc: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/chiliboard_defconfig b/configs/chiliboard_defconfig
index a50e732..ae101da 100644
--- a/configs/chiliboard_defconfig
+++ b/configs/chiliboard_defconfig
@@ -46,6 +46,7 @@
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_REDUNDAND_ENVIRONMENT=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
+CONFIG_NET_RETRY_COUNT=10
 CONFIG_BOOTP_SEND_HOSTNAME=y
 CONFIG_BOOTCOUNT_LIMIT=y
 CONFIG_SYS_I2C_LEGACY=y