Convert CONFIG_CMD_ZFS to Kconfig

This converts the following to Kconfig:
   CONFIG_CMD_ZFS

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>

cmd/Kconfig

@@ -1415,6 +1415,17 @@ config CMD_YAFFS2
 	  that device writes are sequential regardless of filesystem
 	  activity.
 
+config CMD_ZFS
+	bool "zfs - Access of ZFS filesystem"
+	help
+	  This provides commands to accessing a ZFS filesystem, commonly used
+	  on Solaris systems. Two sub-commands are provided:
+
+	    zfsls - list files in a directory
+	    zfsload - load a file
+
+	  See doc/README.zfs for more details.
+
 endmenu
 
 menu "Debug commands"

include/config_cmd_all.h

@@ -13,6 +13,4 @@
  * Alphabetical list of all possible commands.
  */
 
-#define CONFIG_CMD_ZFS		/* ZFS Support			*/
-
 #endif	/* _CONFIG_CMD_ALL_H */

scripts/config_whitelist.txt

@@ -293,7 +293,6 @@ CONFIG_CM922T_XA10
 CONFIG_CMDLINE_EDITING
 CONFIG_CMDLINE_PS_SUPPORT
 CONFIG_CMDLINE_TAG
-CONFIG_CMD_ZFS
 CONFIG_CM_INIT
 CONFIG_CM_MULTIPLE_SSRAM
 CONFIG_CM_REMAP