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_ecm.c b/drivers/usb/gadget/f_ecm.c
index 8ab9e96..7892427 100644
--- a/drivers/usb/gadget/f_ecm.c
+++ b/drivers/usb/gadget/f_ecm.c
@@ -91,7 +91,7 @@
  * encapsulated commands (vendor-specific, using control-OUT).
  */
 
-#define LOG2_STATUS_INTERVAL_MSEC	5	/* 1 << 5 == 32 msec */
+#define ECM_STATUS_INTERVAL_MS		32
 #define ECM_STATUS_BYTECOUNT		16	/* 8 byte header + data */
 
 
@@ -192,7 +192,7 @@
 	.bEndpointAddress =	USB_DIR_IN,
 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 	.wMaxPacketSize =	cpu_to_le16(ECM_STATUS_BYTECOUNT),
-	.bInterval =		1 << LOG2_STATUS_INTERVAL_MSEC,
+	.bInterval =		ECM_STATUS_INTERVAL_MS,
 };
 
 static struct usb_endpoint_descriptor fs_ecm_in_desc = {
@@ -239,7 +239,7 @@
 	.bEndpointAddress =	USB_DIR_IN,
 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 	.wMaxPacketSize =	cpu_to_le16(ECM_STATUS_BYTECOUNT),
-	.bInterval =		LOG2_STATUS_INTERVAL_MSEC + 4,
+	.bInterval =		USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 };
 
 static struct usb_endpoint_descriptor hs_ecm_in_desc = {
@@ -288,7 +288,7 @@
 	.bEndpointAddress =	USB_DIR_IN,
 	.bmAttributes =		USB_ENDPOINT_XFER_INT,
 	.wMaxPacketSize =	cpu_to_le16(ECM_STATUS_BYTECOUNT),
-	.bInterval =		LOG2_STATUS_INTERVAL_MSEC + 4,
+	.bInterval =		USB_MS_TO_HS_INTERVAL(ECM_STATUS_INTERVAL_MS),
 };
 
 static struct usb_ss_ep_comp_descriptor ss_ecm_intr_comp_desc = {