iommu/mediatek: Remove for_each_m4u in tlb_sync_all

The tlb_sync_all is called from these three functions:
a) flush_iotlb_all: it will be called for each a iommu HW.
b) tlb_flush_range_sync: it already has for_each_m4u.
c) in irq: When IOMMU HW translation fault, Only need flush itself.

Thus, No need for_each_m4u in this tlb_sync_all. Remove it.

Signed-off-by: Yong Wu <yong.wu@mediatek.com>
Reviewed-by: Dafna Hirschfeld <dafna.hirschfeld@collabora.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20211208120744.2415-2-dafna.hirschfeld@collabora.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>