regmap: split up regmap_config.use_single_rw

Split regmap_config.use_single_rw into use_single_read and
use_single_write. This change enables drivers of devices which only
support bulk operations in one direction to use the regmap_bulk_*()
functions for both directions and have their bulk operation split into
single operations only when necessary.

Update all struct regmap_config instances where use_single_rw==true to
instead set both use_single_read and use_single_write. No attempt was
made to evaluate whether it is possible to set only one of
use_single_read or use_single_write.

Signed-off-by: David Frey <dpfrey@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/base/regmap/regmap.c

@@ -762,8 +762,8 @@ struct regmap *__regmap_init(struct device *dev,
 		map->reg_stride_order = ilog2(map->reg_stride);
 	else
 		map->reg_stride_order = -1;
-	map->use_single_read = config->use_single_rw || !bus || !bus->read;
-	map->use_single_write = config->use_single_rw || !bus || !bus->write;
+	map->use_single_read = config->use_single_read || !bus || !bus->read;
+	map->use_single_write = config->use_single_write || !bus || !bus->write;
 	map->can_multi_write = config->can_multi_write && bus && bus->write;
 	if (bus) {
 		map->max_raw_read = bus->max_raw_read;