HID: Add support for side buttons of Xiaomi Mi Dual Mode Wireless Mouse Silent

This patch enables side-buttons of Xiaomi Bluetooth mouse (specifically Xiaomi
Mi Dual Mode Wireless Mouse Silent Edition).

The mouse sends invalid button count in its HID Report Descriptor and this
patch just replaces its descriptor with corrected one. With this driver side
buttons work as expected acting like Back/Forward buttons.

Signed-off-by: Ilya Skriblovsky <ilyaskriblovsky@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>