PCI: mediatek-gen3: Fix translation window size calculation

PCI: mediatek-gen3: Fix translation window size calculation

When using the fls() helper, the translation table should be a power of
two; otherwise, the resulting value will not be correct.

For example, given fls(0x3e00000) - 1 = 25, the PCIe translation window
size will be set to 0x2000000 instead of the expected size 0x3e00000.

Fix the translation window by splitting the MMIO space into multiple tables
if its size is not a power of two.

[kwilczynski: commit log]
Link: https://lore.kernel.org/linux-pci/20231023081423.18559-1-jianjun.wang@mediatek.com
Fixes: d3bf75b579b9 ("PCI: mediatek-gen3: Add MediaTek Gen3 driver for MT8192")
Signed-off-by: Jianjun Wang <jianjun.wang@mediatek.com>
Signed-off-by: Krzysztof Wilczyński <kwilczynski@kernel.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>