regmap: A cache type of _NONE behaves like a bypassed cache

Avoid extra special casing by setting the cache_bypass flag when we're
not caching.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/drivers/base/regmap/regcache.c b/drivers/base/regmap/regcache.c
index 00609bf..179f222 100644
--- a/drivers/base/regmap/regcache.c
+++ b/drivers/base/regmap/regcache.c
@@ -82,8 +82,10 @@
 	int i;
 	void *tmp_buf;
 
-	if (map->cache_type == REGCACHE_NONE)
+	if (map->cache_type == REGCACHE_NONE) {
+		map->cache_bypass = true;
 		return 0;
+	}
 
 	for (i = 0; i < ARRAY_SIZE(cache_types); i++)
 		if (cache_types[i]->type == map->cache_type)