regmap: Implementation for regmap_multi_reg_write

This is the implementation of regmap_multi_reg_write()

There is a new capability 'can_multi_write' that device drivers
must set in order to use this multi reg write mode.

This replaces the first definition, which just defined the API.

Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/drivers/base/regmap/internal.h b/drivers/base/regmap/internal.h
index 33414b1..7d13269 100644
--- a/drivers/base/regmap/internal.h
+++ b/drivers/base/regmap/internal.h
@@ -134,6 +134,8 @@
 
 	/* if set, converts bulk rw to single rw */
 	bool use_single_rw;
+	/* if set, the device supports multi write mode */
+	bool can_multi_write;
 
 	struct rb_root range_tree;
 	void *selector_work_buf;	/* Scratch buffer used for selector */