Convert CONFIG_BOOTP_DNS2 to Kconfig

This converts the following to Kconfig:
   CONFIG_BOOTP_DNS2
   CONFIG_BOOTP_PXE_CLIENTARCH

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/devkit8000_defconfig b/configs/devkit8000_defconfig
index 1d642c0..53a43ed 100644
--- a/configs/devkit8000_defconfig
+++ b/configs/devkit8000_defconfig
@@ -20,6 +20,7 @@
 CONFIG_CMD_NAND=y
 CONFIG_CMD_NAND_LOCK_UNLOCK=y
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_BOOTP_DNS2=y
 CONFIG_BOOTP_NTPSERVER=y
 CONFIG_CMD_JFFS2=y
 CONFIG_CMD_MTDPARTS=y