fs: Kconfig: Add a separate option for FS_CRAMFS

Rather than using CMD_CRAMFS for both the filesystem and its command, we
should have a separate option for each. This allows us to enable CRAMFS
support without the command, if desired, which reduces U-Boot's size
slightly.

Signed-off-by: Simon Glass <sjg@chromium.org>
[trini: imply FS_CRAMFS for keymile]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/fs/cramfs/Kconfig b/fs/cramfs/Kconfig
index e69de29..6c9f63d 100644
--- a/fs/cramfs/Kconfig
+++ b/fs/cramfs/Kconfig
@@ -0,0 +1,7 @@
+config FS_CRAMFS
+	bool "Enable CRAMFS filesystem support"
+	help
+	  This provides support for reading images from CRAMFS (Compressed ROM
+	  filesystem). CRAMFS is useful when space is tight since files are
+	  compressed. You can also enable CMD_CRAMFS to get command-line
+	  access.