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/origen_defconfig b/configs/origen_defconfig
index fe9fc33..83a83ab 100644
--- a/configs/origen_defconfig
+++ b/configs/origen_defconfig
@@ -16,7 +16,7 @@
 CONFIG_IDENT_STRING=" for ORIGEN"
 CONFIG_DISTRO_DEFAULTS=y
 CONFIG_SYS_LOAD_ADDR=0x43e00000
-# CONFIG_USE_BOOTCOMMAND is not set
+CONFIG_BOOTCOMMAND="if mmc rescan; then echo SD/MMC found on device ${mmcdev};if run loadbootenv; then echo Loaded environment from ${bootenv};run importbootenv;fi;if test -n $uenvcmd; then echo Running uenvcmd ...;run uenvcmd;fi;if run loadbootscript; then run bootscript; fi; fi;load mmc ${mmcdev} ${loadaddr} uImage; bootm ${loadaddr} "
 CONFIG_SYS_CONSOLE_IS_IN_ENV=y
 CONFIG_SYS_CONSOLE_INFO_QUIET=y
 # CONFIG_SPL_FRAMEWORK is not set