usb: gadget: use a computation macro for INT endpoint interval

The 5+4 magic for HS tries to aim 32ms which is also what is intended
with 1 << 5 for FS. This little macro should make this easier to
understand.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/gadget/f_ncm.c b/drivers/usb/gadget/f_ncm.c
index b651b52..4f09500 100644
--- a/drivers/usb/gadget/f_ncm.c
+++ b/drivers/usb/gadget/f_ncm.c
@@ -121,7 +121,7 @@
  * waste less bandwidth.
  */
 
-#define LOG2_STATUS_INTERVAL_MSEC	5	/* 1 << 5 == 32 msec */
+#define NCM_STATUS_INTERVAL_MS		32
 #define NCM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
 
 static struct usb_interface_assoc_descriptor ncm_iad_desc __initdata = {
@@ -230,7 +230,7 @@
 	.bEndpointAddress =	USB_DIR_IN,
 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
-	.bInterval =		1 << LOG2_STATUS_INTERVAL_MSEC,
+	.bInterval =		NCM_STATUS_INTERVAL_MS,
 };
 
 static struct usb_endpoint_descriptor fs_ncm_in_desc __initdata = {
@@ -275,7 +275,7 @@
 	.bEndpointAddress =	USB_DIR_IN,
 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 	.wMaxPacketSize =	cpu_to_le16(NCM_STATUS_BYTECOUNT),
-	.bInterval =		LOG2_STATUS_INTERVAL_MSEC + 4,
+	.bInterval =		USB_MS_TO_HS_INTERVAL(NCM_STATUS_INTERVAL_MS),
 };
 static struct usb_endpoint_descriptor hs_ncm_in_desc __initdata = {
 	.bLength =		USB_DT_ENDPOINT_SIZE,