usb: s/CONFIG_DM_USB/CONFIG_IS_ENABLED(DM_USB)/

This allows to disable the USB driver model in SPL because it checks
the CONFIG_SPL_DM_USB variable for SPL builds. Nothing changes for
regular non-SPL builds.

Signed-off-by: Sven Schwermer <sven@svenschwermer.de>
diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 6ea9f10..3b6f889 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -120,7 +120,7 @@
 #define invalidate_dcache_iso_td(addr) invalidate_dcache_buffer(addr, 32)
 #define invalidate_dcache_hcca(addr) invalidate_dcache_buffer(addr, 256)
 
-#ifdef CONFIG_DM_USB
+#if CONFIG_IS_ENABLED(DM_USB)
 /*
  * The various ohci_mdelay(1) calls in the code seem unnecessary. We keep
  * them around when building for older boards not yet converted to the dm
@@ -131,7 +131,7 @@
 #define ohci_mdelay(x) mdelay(x)
 #endif
 
-#ifndef CONFIG_DM_USB
+#if !CONFIG_IS_ENABLED(DM_USB)
 /* global ohci_t */
 static ohci_t gohci;
 /* this must be aligned to a 256 byte boundary */
@@ -1691,7 +1691,7 @@
 	return 0;
 }
 
-#ifndef CONFIG_DM_USB
+#if !CONFIG_IS_ENABLED(DM_USB)
 /* submit routines called from usb.c */
 int submit_bulk_msg(struct usb_device *dev, unsigned long pipe, void *buffer,
 		int transfer_len)
@@ -1980,7 +1980,7 @@
 
 /*-------------------------------------------------------------------------*/
 
-#ifndef CONFIG_DM_USB
+#if !CONFIG_IS_ENABLED(DM_USB)
 
 /*-------------------------------------------------------------------------*/
 
@@ -2130,7 +2130,7 @@
 }
 #endif
 
-#ifdef CONFIG_DM_USB
+#if CONFIG_IS_ENABLED(DM_USB)
 static int ohci_submit_control_msg(struct udevice *dev, struct usb_device *udev,
 				   unsigned long pipe, void *buffer, int length,
 				   struct devrequest *setup)