usb: Drop old non-DM code

The driver model deadline for USB was in 2019, so drop the old USB
keyboard code, to avoid needing to deal with the extra code path.

Drop the unnecessary #ifdef around USB_KBD_BOOT_REPORT_SIZE while we
are here.

Signed-off-by: Simon Glass <sjg@chromium.org>

include/usb.h

@@ -250,20 +250,12 @@ int usb_host_eth_scan(int mode);
 
 #endif
 
-#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);
-
-#endif
-/* routines */
-
 /*
  * usb_init() - initialize the USB Controllers
  *