General help message cleanup

Many of the help messages were not really helpful; for example, many
commands that take no arguments would not print a correct synopsis
line, but "No additional help available." which is not exactly wrong,
but not helpful either.

Commit ``Make "usage" messages more helpful.'' changed this
partially. But it also became clear that lots of "Usage" and "Help"
messages (fields "usage" and "help" in struct cmd_tbl_s respective)
were actually redundant.

This patch cleans this up - for example:

Before:
	=> help dtt
	dtt - Digital Thermometer and Thermostat

	Usage:
	dtt         - Read temperature from digital thermometer and thermostat.

After:
	=> help dtt
	dtt - Read temperature from Digital Thermometer and Thermostat

	Usage:
	dtt

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/drivers/qe/qe.c b/drivers/qe/qe.c
index f114fe0..918bfa7 100644
--- a/drivers/qe/qe.c
+++ b/drivers/qe/qe.c
@@ -473,5 +473,6 @@
 	qe, 4, 0, qe_cmd,
 	"QUICC Engine commands",
 	"fw <addr> [<length>] - Upload firmware binary at address <addr> to "
-		"the QE,\n\twith optional length <length> verification.\n"
-	);
+		"the QE,\n"
+	"\twith optional length <length> verification."
+);