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/kgdb.c b/common/kgdb.c
index adc15dd..888b96b 100644
--- a/common/kgdb.c
+++ b/common/kgdb.c
@@ -575,7 +575,7 @@
 
 U_BOOT_CMD(
 	kgdb, CONFIG_SYS_MAXARGS, 1,	do_kgdb,
-	"kgdb    - enter gdb remote debug mode\n",
+	"enter gdb remote debug mode",
 	"[arg0 arg1 .. argN]\n"
 	"    - executes a breakpoint so that kgdb mode is\n"
 	"      entered via the exception handler. To return\n"