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/ls2080ardb_defconfig b/configs/ls2080ardb_defconfig
index 9216ffb..9b323c6 100644
--- a/configs/ls2080ardb_defconfig
+++ b/configs/ls2080ardb_defconfig
@@ -17,7 +17,7 @@
 CONFIG_BOOTDELAY=10
 CONFIG_USE_BOOTARGS=y
 CONFIG_BOOTARGS="console=ttyS1,115200 root=/dev/ram0 earlycon=uart8250,mmio,0x21c0600 ramdisk_size=0x2000000 default_hugepagesz=2m hugepagesz=2m hugepages=256"
-# CONFIG_USE_BOOTCOMMAND is not set
+CONFIG_BOOTCOMMAND="env exists mcinitcmd && env exists secureboot && esbc_validate 0x5806C0000; env exists mcinitcmd && fsl_mc lazyapply dpl 0x580d00000;run distro_bootcmd;run nor_bootcmd; env exists secureboot && esbc_halt;"
 CONFIG_MISC_INIT_R=y
 CONFIG_CMD_IMLS=y
 CONFIG_CMD_GREPENV=y