HID: hyperv: Set the hid drvdata correctly

Set the hid drvdata prior to invoking hid_add_device() as hid_add_device()
expects this state to be set. This bug was introduced in the recent hid
changes that were made in 07d9ab4f ("HID: hid-hyperv: Do not use
hid_parse_report() directly").

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