UBIFS: Add UBIFS commands

This patchset adds these UBIFS related commands:

- ubifsmount
  Mount an UBIFS volume

- ubifsls
  List a directory of the mounted UBIFS volume

- ubifsload
  Load a file from the mounted UBIFS volume to memory

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/common/Makefile b/common/Makefile
index 7237ff4..23171ca 100644
--- a/common/Makefile
+++ b/common/Makefile
@@ -130,6 +130,7 @@
 COBJS-$(CONFIG_CMD_STRINGS) += cmd_strings.o
 COBJS-$(CONFIG_CMD_TERMINAL) += cmd_terminal.o
 COBJS-$(CONFIG_CMD_UBI) += cmd_ubi.o
+COBJS-$(CONFIG_CMD_UBIFS) += cmd_ubifs.o
 COBJS-$(CONFIG_CMD_UNIVERSE) += cmd_universe.o
 ifdef CONFIG_CMD_USB
 COBJS-y += cmd_usb.o