ANDROID: abi_gki_aarch64_mtk: Remove execute permissions

When this was uploaded, it was mistakenly made executable. Fix that.

Fixes: 78a9cd65 ("ANDROID: add initial symbol list for mtk")
Signed-off-by: J. Avila <elavila@google.com>
Change-Id: I24be8828e25a8262b513857b11e997f40a0a6a68