iommu/apple-dart: Use readl instead of readl_relaxed for consistency

While the readl_relaxed in apple_dart_suspend is correct the rest of the
driver uses the non-relaxed variants everywhere and the single
readl_relaxed is inconsistent and possibly confusing.

Signed-off-by: Sven Peter <sven@svenpeter.dev>
Acked-by: Hector Martin <marcan@marcan.st>
Reviewed-by: Neal Gompa <neal@gompa.dev>
Link: https://lore.kernel.org/r/20231126162009.17934-1-sven@svenpeter.dev
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Author: svenpeter42

drivers/iommu/apple-dart.c

@@ -1302,7 +1302,7 @@ static __maybe_unused int apple_dart_suspend(struct device *dev)
 	unsigned int sid, idx;
 
 	for (sid = 0; sid < dart->num_streams; sid++) {
-		dart->save_tcr[sid] = readl_relaxed(dart->regs + DART_TCR(dart, sid));
+		dart->save_tcr[sid] = readl(dart->regs + DART_TCR(dart, sid));
 		for (idx = 0; idx < dart->hw->ttbr_count; idx++)
 			dart->save_ttbr[sid][idx] =
 				readl(dart->regs + DART_TTBR(dart, sid, idx));