usb_cdc_ep: Define endpoint sizes in usb_cdc_ep.h

Move the definition of the usb endpoint sizes from usb_cdc.h to
usb_cdc_ep.h .  This allows individual boards to override the default
endpoint sizes.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/lpc176x/usb_cdc_ep.h

@@ -7,4 +7,11 @@ enum {
     USB_CDC_EP_BULK_IN = 5,
 };
 
+enum {
+    USB_CDC_EP0_SIZE = 16,
+    USB_CDC_EP_ACM_SIZE = 8,
+    USB_CDC_EP_BULK_OUT_SIZE = 64,
+    USB_CDC_EP_BULK_IN_SIZE = 64,
+};
+
 #endif // usb_cdc_ep.h