hw/usb/dev-hid: Support side and extra mouse buttons for usb-tablet

The necessary plumbing for side- and extra mouse buttons to reach
usb-tablet is already done. But the descriptor advertises three buttons
max. Increase this to 5. Buttons are now identical to usb-mouse.

Signed-off-by: Thomas Lambertz <patch@thomaslambertz.de>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
1 file changed