Convert CONFIG_BOOTP_MAY_FAIL et al to Kconfig

This converts the following to Kconfig:
   CONFIG_BOOTP_MAY_FAIL
   CONFIG_BOOTP_VENDOREX
   CONFIG_BOOTP_BOOTFILESIZE
   CONFIG_BOOTP_NISDOMAIN
   CONFIG_BOOTP_TIMEOFFSET

Cc: Ramon Fried <rfried.dev@gmail.com>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/theadorable-x86-dfi-bt700_defconfig b/configs/theadorable-x86-dfi-bt700_defconfig
index 78b8fdb..9dd2d4f 100644
--- a/configs/theadorable-x86-dfi-bt700_defconfig
+++ b/configs/theadorable-x86-dfi-bt700_defconfig
@@ -32,6 +32,7 @@
 CONFIG_CMD_SPI=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_DHCP=y
+CONFIG_BOOTP_BOOTFILESIZE=y
 # CONFIG_CMD_NFS is not set
 CONFIG_CMD_PING=y
 CONFIG_CMD_BMP=y