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_reginfo.c b/common/cmd_reginfo.c
index 4c8e61a..0e28c05 100644
--- a/common/cmd_reginfo.c
+++ b/common/cmd_reginfo.c
@@ -382,6 +382,6 @@
 #if defined(CONFIG_CMD_REGINFO)
 U_BOOT_CMD(
 	reginfo,	2,	1,	do_reginfo,
-	"reginfo - print register information\n",
+	"print register information",
 );
 #endif