mmu: flush ttb in map_io_sections

We need to flush out the ttb in order to make the
changes observable to the page walker.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

arch/arm/cpu/mmu.c

@@ -188,6 +188,7 @@ void *map_io_sections(unsigned long phys, void *_start, size_t size)
 	for (sec = start; sec < start + size; sec += (1 << 20))
 		ttb[sec >> 20] = (phys++ << 20) | PMD_SECT_DEF_UNCACHED;
 
+	dma_flush_range((unsigned long)ttb, (unsigned long)ttb + 0x4000);
 	tlb_invalidate();
 	return _start;
 }