FROMLIST: dt-bindings: display: mediatek: add EXDMA yaml for MT8196

Add mediatek,exdma.yaml to support EXDMA for MT8196.

Signed-off-by: Paul-pl.Chen <paul-pl.chen@mediatek.com>
(am from https://patchwork.kernel.org/patch/13935618/)
(also found at https://lore.kernel.org/r/20250110123835.2719824-4-paul-pl.chen@mediatek.com

)

BUG=b:384077322
TEST=emerge-rauru sys-kernel/chromeos-kernel-6_6
UPSTREAM-TASK=b:379039599

Signed-off-by: Paul-PL Chen <paul-pl.chen@mediatek.corp-partner.google.com>
Change-Id: Id1597914954382176714a41993555a9bd76d3a04
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/third_party/kernel/+/6181668


Commit-Queue: Eric Yilun Lin <yllin@google.com>
Reviewed-by: Pin-yen Lin <treapking@chromium.org>
Tested-by: Eric Yilun Lin <yllin@google.com>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: Hubert Mazur <hmazur@google.com>