ipc/client: Check device_type for HMD instead of device name
Not all HMDs are `GENERIC_HMD`, and some HMD drivers are now starting to
use non-`GENERIC_HMD` device names, so this makes them initialize as
HMDs correctly.
Part-of: <https://gitlab.freedesktop.org/monado/monado/-/merge_requests/2610>