HID: magicmouse: fix reconnection of Magic Mouse 2

It is observed that the Magic Mouse 2 would not enter multi-touch mode
unless the mouse is connected before loading the module. It seems to be
a quirk specific to Magic Mouse 2

Retrying after 500ms fixes the problem for me. The delay can't be
reduced much further --- 300ms didn't work for me. Retrying immediately
after receiving an event didn't work either.

Signed-off-by: John Chen <johnchen902@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>