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/esd/cpci750/cpci750.c b/board/esd/cpci750/cpci750.c
index 70bae60..4826633 100644
--- a/board/esd/cpci750/cpci750.c
+++ b/board/esd/cpci750/cpci750.c
@@ -993,6 +993,6 @@
 
 U_BOOT_CMD(
 	show_config,	1,	1,	do_show_config,
-	"show_config - Show Marvell strapping register\n",
+	"Show Marvell strapping register",
 	"Show Marvell strapping register (ResetSampleLow ResetSampleHigh)\n"
 	);