HID: hv_mouse: Properly add the hid device

We need to properly add the hid device to correctly initialize the sysfs state.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Reported-by: Fuzhou Chen <fuzhouch@microsoft.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>