dt-bindings: dma: nvidia,tegra186-gpc-dma: Make reset optional

dt-bindings: dma: nvidia,tegra186-gpc-dma: Make reset optional

On Tegra264, GPCDMA reset control is not exposed to Linux and is handled
by the boot firmware.

Although reset was not exposed in Tegra234 as well, the firmware supported
a dummy reset which just returns success on reset without doing an actual
reset. This is also not supported in Tegra264 BPMP. Therefore mark 'reset'
and 'reset-names' properties as required only for devices prior to
Tegra264.

This also necessitates that the Tegra264 compatible be standalone and
cannot have the fallback compatible of Tegra186. Since there is no
functional impact, we keep reset as required for Tegra234 to avoid
breaking the ABI.

Fixes: bb8c97571db5 ("dt-bindings: dma: Add Tegra264 compatible string")
Signed-off-by: Akhil R <akhilrajeev@nvidia.com>
Acked-by: Rob Herring (Arm) <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Link: https://patch.msgid.link/20260331102303.33181-2-akhilrajeev@nvidia.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>