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/pic32mzdask_defconfig b/configs/pic32mzdask_defconfig
index 9d5aa3a..4efddc0 100644
--- a/configs/pic32mzdask_defconfig
+++ b/configs/pic32mzdask_defconfig
@@ -24,6 +24,7 @@
 CONFIG_CMD_GPIO=y
 CONFIG_CMD_MMC=y
 CONFIG_CMD_USB=y
+CONFIG_BOOTP_BOOTFILESIZE=y
 CONFIG_CMD_RARP=y
 CONFIG_CMD_TIME=y
 CONFIG_CMD_EXT4_WRITE=y