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/k2l_hs_evm_defconfig b/configs/k2l_hs_evm_defconfig
index d4d8024..718ceff 100644
--- a/configs/k2l_hs_evm_defconfig
+++ b/configs/k2l_hs_evm_defconfig
@@ -15,6 +15,8 @@
 CONFIG_DEFAULT_DEVICE_TREE="keystone-k2l-evm"
 CONFIG_FIT_IMAGE_POST_PROCESS=y
 CONFIG_OF_BOARD_SETUP=y
+CONFIG_USE_BOOTCOMMAND=y
+CONFIG_BOOTCOMMAND="run run_mon_hs; run init_${boot}; run get_fit_${boot}; bootm ${addr_fit}#${name_fdt}"
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 CONFIG_BOARD_EARLY_INIT_F=y
 CONFIG_HUSH_PARSER=y