Move all command code into its own directory

There are a lot of unrelated files in common, including all of the commands.
Moving them into their own directory makes them easier to find and is more
logical.

Some commands include non-command code, such as cmd_scsi.c. This should be
sorted out at some point so that the function can be enabled with or without
the associated command.

Unfortunately, with m68k I get this error:

m68k:  +   M5329AFEE
+arch/m68k/cpu/mcf532x/start.o: In function `_start':
+arch/m68k/cpu/mcf532x/start.S:159:(.text+0x452): relocation truncated to fit: R_68K_PC16 against symbol `board_init_f' defined in .text.board_init_f section in common/built-in.o

I hope someone can shed some light on what this means. I hope it isn't
depending on the position of code in the image.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Heiko Schocher <hs@denx.de>
Acked-by: Stefan Roese <sr@denx.de>
Acked-by: Przemyslaw Marczak <p.marczak@samsung.com>

cmd/cmd_console.c

@@ -0,0 +1,53 @@
+/*
+ * (C) Copyright 2000
+ * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/*
+ * Boot support
+ */
+#include <common.h>
+#include <command.h>
+#include <stdio_dev.h>
+
+extern void _do_coninfo (void);
+static int do_coninfo(cmd_tbl_t *cmd, int flag, int argc, char * const argv[])
+{
+	int l;
+	struct list_head *list = stdio_get_list();
+	struct list_head *pos;
+	struct stdio_dev *dev;
+
+	/* Scan for valid output and input devices */
+
+	puts ("List of available devices:\n");
+
+	list_for_each(pos, list) {
+		dev = list_entry(pos, struct stdio_dev, list);
+
+		printf ("%-8s %08x %c%c ",
+			dev->name,
+			dev->flags,
+			(dev->flags & DEV_FLAGS_INPUT) ? 'I' : '.',
+			(dev->flags & DEV_FLAGS_OUTPUT) ? 'O' : '.');
+
+		for (l = 0; l < MAX_FILES; l++) {
+			if (stdio_devices[l] == dev) {
+				printf ("%s ", stdio_names[l]);
+			}
+		}
+		putc ('\n');
+	}
+	return 0;
+}
+
+
+/***************************************************/
+
+U_BOOT_CMD(
+	coninfo,	3,	1,	do_coninfo,
+	"print console devices and information",
+	""
+);