bloblist: Add a command

It is helpful to be able to see basic statistics about the bloblist and
also to list its contents. Add a 'bloblist' command to handle this.

Put the display functions in the bloblist modules rather than in the
command code itself. That allows showing a list from SPL, where commands
are not available.

Also make bloblist_first/next_blob() static as they are not used outside
this file.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 999b6cf..b25d2b0 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -631,6 +631,15 @@
 	  Compute binary operations (xor, or, and) of byte arrays of arbitrary
 	  size from memory and store the result in memory or the environment.
 
+config CMD_BLOBLIST
+	bool "bloblist"
+	default y if BLOBLIST
+	help
+	  Show information about the bloblist, a collection of binary blobs
+	  held in memory that persist between SPL and U-Boot. In the case of
+	  x86 devices the bloblist can be used to hold ACPI tables so that they
+	  remain available in memory.
+
 config CMD_CRC32
 	bool "crc32"
 	default y