usb: chipidea: trim include list in udc code

Some headers included in udc core code are not actually needed, remove
them and add irqreturn.h, which was implicitly included via irq.h.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c
index f64fbea..3dc5093 100644
--- a/drivers/usb/chipidea/udc.c
+++ b/drivers/usb/chipidea/udc.c
@@ -13,14 +13,8 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dmapool.h>
-#include <linux/dma-mapping.h>
 #include <linux/err.h>
-#include <linux/init.h>
-#include <linux/platform_device.h>
-#include <linux/module.h>
-#include <linux/interrupt.h>
-#include <linux/io.h>
-#include <linux/irq.h>
+#include <linux/irqreturn.h>
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/pm_runtime.h>