cmd: Add 2048 game

Add the 2048 game, a good demo of ANSI sequences and a way to waste a
little time.

Bring it it from Barebox, modified for code style.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 091a0ee..e45b884 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -1941,6 +1941,17 @@
 
 menu "Misc commands"
 
+config CMD_2048
+	bool "Play 2048"
+	help
+	  This is a simple sliding block puzzle game designed by Italian web
+	  developer Gabriele Cirulli. The game's objective is to slide numbered
+	  tiles on a grid to combine them to create a tile with the number
+	  2048.
+
+	  This needs ANSI support on your terminal to work. It is not fully
+	  functional on a video device.
+
 config CMD_BMP
 	bool "Enable 'bmp' command"
 	depends on VIDEO