drm/panfrost: Force AARCH64_4K page table format on MediaTek MT8188

MediaTek MT8188 SoC has an ARM Mali-G57 MC3 GPU (Valhall-JM), which
constantly faults with the current panfrost support.

For instance, running `glmark2-es2-drm` benchmark test:
```
[   79.617461] panfrost 13000000.gpu: js fault, js=1, status=JOB_BUS_FAULT, head=0xaadc380, tail=0xaadc380
[   80.119811] panfrost 13000000.gpu: gpu sched timeout, js=0, config=0x7300, status=0x58, head=0xaaca180, tail=0xaaca180, sched_job=000000002fd03ccc
[   80.129083] panfrost 13000000.gpu: Unhandled Page fault in AS0 at VA 0x0000000000000000
[   80.129083] Reason: TODO
[   80.129083] raw fault status: 0x1C2
[   80.129083] decoded fault status: SLAVE FAULT
[   80.129083] exception type 0xC2: TRANSLATION_FAULT_2
[   80.129083] access type 0x1: EXECUTE
[   80.129083] source id 0x0
```

Note that current panfrost mode (Mali LPAE - LEGACY) only allows to
specify write-cache or implementation-defined as the caching policy,
probably not matching the right configuration. As depicted in the source
code:

drivers/iommu/io-pgtable-arm.c:
```
* MEMATTR: Mali has no actual notion of a non-cacheable type, so the
* best we can do is mimic the out-of-tree driver and hope that the
* "implementation-defined caching policy" is good enough...
```

Now that Panfrost supports AARCH64_4K page table format, let's enable it
on Mediatek MT8188 and configure the cache/shareability policies
properly.

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://lore.kernel.org/r/20250324185801.168664-6-ariel.dalessandro@collabora.com