gpu: host1x: Export public API

Make the public API symbols visible so that depending drivers can be
built as a module.

Signed-off-by: Thierry Reding <treding@nvidia.com>

diff --cc drivers/gpu/host1x/bus.c
Simple merge

diff --cc drivers/gpu/host1x/channel.c
Simple merge

diff --cc drivers/gpu/host1x/job.c
Simple merge

diff --cc drivers/gpu/host1x/syncpt.c
Simple merge