drm/tyr: Remove custom register struct

drm/tyr: Remove custom register struct

Now that Tyr uses the register! macro, it no longer needs to define a
custom register struct or read/write functions, so delete them.

Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Co-developed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Deborah Brouwer <deborah.brouwer@collabora.com>
Link: https://patch.msgid.link/20260409-b4-tyr-use-register-macro-v5-v5-5-8abfff8a0204@collabora.com
Signed-off-by: Alice Ryhl <aliceryhl@google.com>