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/pg_wcom_seli8_defconfig b/configs/pg_wcom_seli8_defconfig
index 1a2ba8c..56db37b 100644
--- a/configs/pg_wcom_seli8_defconfig
+++ b/configs/pg_wcom_seli8_defconfig
@@ -45,6 +45,7 @@
 CONFIG_CMD_I2C=y
 CONFIG_CMD_NAND=y
 CONFIG_CMD_NAND_TRIMFFS=y
+CONFIG_BOOTP_BOOTFILESIZE=y
 CONFIG_CMD_CRAMFS=y
 CONFIG_CMD_MTDPARTS=y
 CONFIG_MTDIDS_DEFAULT="nor0=60000000.nor,nand0=68000000.flash"