drm/tegra: gr2d: Explicitly control module reset

drm/tegra: gr2d: Explicitly control module reset

As of commit 4c1b7c284be5 ("clk: tegra: Don't deassert reset on enabling
clocks"), module resets are no longer automatically deasserted when the
module clock is enabled. To make sure that the gr2d module continues to
work, we need to explicitly control the module reset.

Fixes: 4c1b7c284be5 ("clk: tegra: Don't deassert reset on enabling clocks")
Signed-off-by: Thierry Reding <treding@nvidia.com>