drm/tyr: Use DRM device type alias across driver

drm/tyr: Use DRM device type alias across driver

Currently Tyr defines a convenience type alias for its DRM device type,
`TyrDrmDevice` but it does not use the alias outside of `tyr/driver.rs`.

Replace `drm::Device<TyrDrmDriver>` with the alias `TyrDrmDevice` across
the driver.

This change will ease future upstream Tyr development by reducing the
diffs when multiple series are touching these files.

No functional changes are intended.

Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Link: https://patch.msgid.link/20260302202331.176140-1-deborah.brouwer@collabora.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>