edid: switch to a statically allocated extension array
The spec defines an upper bound for the extension block count, which means we don't need to dynamically allocate the array. This simplifies our logic a bit by removing an allocation error codepath.
The array is NULL-terminated, so EDID_MAX_BLOCK_COUNT is suitable since it's the max number of extension blocks including the base block, and the array doesn't include the base block.
Signed-off-by: Simon Ser contact@emersion.fr