dt-bindings: display: nxp,tda998x: Fix 'audio-ports' constraints

The constraints for 'audio-ports' don't match the description. There can
be 1 or 2 DAI entries and each entry is exactly 2 values. Also, the
values' sizes are 32-bits, not 8-bits. Move the size constraints to the
outer dimension (number of DAIs) and add constraints on inner array
values.

Link: https://lore.kernel.org/r/20240122204959.1665970-1-robh@kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>