usb: kbd: move USB_KBD_BOOT_REPORT_SIZE to usb.h

Move constant USB_KBD_BOOT_REPORT_SIZE. This allows us to reuse it.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/usb.h

@@ -242,6 +242,12 @@ int usb_host_eth_scan(int mode);
 
 #ifdef CONFIG_USB_KEYBOARD
 
+/*
+ * USB Keyboard reports are 8 bytes in boot protocol.
+ * Appendix B of HID Device Class Definition 1.11
+ */
+#define USB_KBD_BOOT_REPORT_SIZE 8
+
 int drv_usb_kbd_init(void);
 int usb_kbd_deregister(int force);