Convert CONFIG_USE_BOOTCOMMAND et al to Kconfig

This converts the following to Kconfig:
   CONFIG_USE_BOOTCOMMAND
   CONFIG_BOOTCOMMAND
   CONFIG_RAMBOOTCOMMAND
   CONFIG_NFSBOOTCOMMAND

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/configs/dfi-bt700-q7x-151_defconfig b/configs/dfi-bt700-q7x-151_defconfig
index 268fbfe..3af6c04 100644
--- a/configs/dfi-bt700-q7x-151_defconfig
+++ b/configs/dfi-bt700-q7x-151_defconfig
@@ -21,6 +21,8 @@
 CONFIG_SHOW_BOOT_PROGRESS=y
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="root=/dev/sda1 ro quiet"
+CONFIG_USE_BOOTCOMMAND=y
+CONFIG_BOOTCOMMAND="load scsi 0:1 03000000 /boot/vmlinuz-${kernel-ver}-generic;load scsi 0:1 04000000 /boot/initrd.img-${kernel-ver}-generic;run boot"
 CONFIG_USE_PREBOOT=y
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_DISPLAY_BOARDINFO_LATE=y