iommu/mediatek: Remove the power status checking in tlb flush all

To simplify the code, Remove the power status checking in the
tlb_flush_all, remove this:
   if (pm_runtime_get_if_in_use(data->dev) <= 0)
	    continue;

The mtk_iommu_tlb_flush_all is called from
a) isr
b) tlb flush range fail case
c) iommu_create_device_direct_mappings

In first two cases, the power and clock are always enabled.
In the third case tlb flush is unnecessary because in a later patch
in the series a full flush from the pm_runtime_resume callback is added.

In addition, writing the tlb control register when the iommu is not resumed
is ok and the write is ignored.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
[refactor commit log]
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20211208120744.2415-4-dafna.hirschfeld@collabora.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>