drm/tegra: dpaux: Populate AUX bus

[ Upstream commit 8913e1ae ]

The DPAUX hardware block exposes an DP AUX interface that provides
access to an AUX bus and the devices on that bus. Use the DP AUX bus
infrastructure that was recently introduced to probe devices on this
bus from DT.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Stable-dep-of: 0800880f ("drm/tegra: dpaux: Fix PM disable depth imbalance in tegra_dpaux_probe")
Signed-off-by: Sasha Levin <sashal@kernel.org>