ARM: tegra: acer-a500: Rename avdd to vdda of touchscreen node

ARM: tegra: acer-a500: Rename avdd to vdda of touchscreen node

BugLink: https://bugs.launchpad.net/bugs/1928857
[ Upstream commit b27b9689e1f3278919c6183c565d837d0aef6fc1 ]

Rename avdd supply to vdda of the touchscreen node. The old supply name
was incorrect.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>