mesa: update aarch64 patch

[meme]

On Xorg applications like Firefox, this buffer increase is
not adequate; it continues to artefact. Increase the size to
1024 * 1024.

General

• This is a new package and it conforms to the quality requirements

Have the results of the proposed changes been tested?

• I use the packages affected by the proposed changes on a regular basis and confirm this PR works for me
• I generally don't use the affected packages but briefly tested this PR

[ericonr]

@q66 could you review this change, please? I have no idea if it's ok to increase it.