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/sandburst/common/ppc440gx_i2c.c b/board/sandburst/common/ppc440gx_i2c.c
index 9af6b8d..c1af70c 100644
--- a/board/sandburst/common/ppc440gx_i2c.c
+++ b/board/sandburst/common/ppc440gx_i2c.c
@@ -500,7 +500,7 @@
 
 U_BOOT_CMD(
 	iprobe1,	1,	1,	do_i2c1_probe,
-	"iprobe1  - probe to discover valid I2C chip addresses\n",
+	"probe to discover valid I2C chip addresses",
 	"\n    -discover valid I2C chip addresses\n"
 );