virtio-gpu: Support context-init feature with virglrenderer

virtio-gpu: Support context-init feature with virglrenderer

Patch "virtio-gpu: CONTEXT_INIT feature" has added the context_init
feature flags. Expose this feature and support creating virglrenderer
context with flags using context_id if libvirglrenderer is new enough.

Originally-by: Antonio Caggiano <antonio.caggiano@collabora.com>
Signed-off-by: Huang Rui <ray.huang@amd.com>
Reviewed-by: Antonio Caggiano <quic_acaggian@quicinc.com>
Signed-off-by: Dmitry Osipenko <dmitry.osipenko@collabora.com>
Message-Id: <20241024210311.118220-8-dmitry.osipenko@collabora.com>
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>