Command usage cleanup

Remove command name from all command "usage" fields and update
common/command.c to display "name - usage" instead of
just "usage". Also remove newlines from command usage fields.

Signed-off-by: Peter Tyser <ptyser@xes-inc.com>
diff --git a/board/amcc/taihu/update.c b/board/amcc/taihu/update.c
index 52bad56..8e96905 100644
--- a/board/amcc/taihu/update.c
+++ b/board/amcc/taihu/update.c
@@ -127,6 +127,6 @@
 
 U_BOOT_CMD (
 	update_boot_eeprom, 1, 1, update_boot_eeprom,
-	"update_boot_eeprom  - update boot eeprom content\n",
+	"update boot eeprom content",
 	NULL
 	);