Fix remaining CFG_CMD_ define, ifdef and comments

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
diff --git a/common/cmd_bootm.c b/common/cmd_bootm.c
index 1c0a416..4040a69 100644
--- a/common/cmd_bootm.c
+++ b/common/cmd_bootm.c
@@ -36,7 +36,7 @@
 #include <lmb.h>
 #include <asm/byteorder.h>
 
-#if (CONFIG_COMMANDS & CFG_CMD_USB)
+#if (CONFIG_CMD_USB)
 #include <usb.h>
 #endif
 
@@ -217,7 +217,7 @@
 	 */
 	iflag = disable_interrupts();
 
-#if (CONFIG_COMMANDS & CFG_CMD_USB)
+#if (CONFIG_CMD_USB)
 	/*
 	 * turn off USB to prevent the host controller from writing to the
 	 * SDRAM while Linux is booting. This could happen (at least for OHCI