rust: drm: add FEAT_RENDER flag for render node support

rust: drm: add FEAT_RENDER flag for render node support

Add FEAT_RENDER bool constant to the Driver trait to control
render node support. When enabled, the driver exposes /dev/dri/renderDXX
render nodes to userspace. The flag defaults to false, drivers can opt
in by setting it to true in their Driver implementation.

This is then enabled in the Tyr driver, while it's left disabled for
Nova for the time being.

Co-developed-by: Daniel Almeida <daniel.almeida@collabora.com>
Signed-off-by: Daniel Almeida <daniel.almeida@collabora.com>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Link: https://patch.msgid.link/20260507080914.95478-2-laura.nao@collabora.com
Signed-off-by: Danilo Krummrich <dakr@kernel.org>