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/common/cmd_mp.c b/common/cmd_mp.c
index d8e3ab2..a0839c2 100644
--- a/common/cmd_mp.c
+++ b/common/cmd_mp.c
@@ -83,7 +83,7 @@
 
 U_BOOT_CMD(
 	cpu, CONFIG_SYS_MAXARGS, 1, cpu_cmd,
-	"cpu     - Multiprocessor CPU boot manipulation and release\n",
+	"Multiprocessor CPU boot manipulation and release",
 	    "<num> reset                 - Reset cpu <num>\n"
 	"cpu <num> status                - Status of cpu <num>\n"
 	"cpu <num> release <addr> [args] - Release cpu <num> at <addr> with [args]\n"