regmap: cache: Step by stride in default sync

The default sync operation was still assuming a stride of one, fix it
to respect the reg_stride set in the map.

Signed-off-by: Dylan Reid <[e-mail]>
Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regcache.c

···
 {
 	unsigned int reg;
 
-	for (reg = min; reg <= max; reg++) {
+	for (reg = min; reg <= max; reg += map->reg_stride) {
 		unsigned int val;
 		int ret;