regmap: add regmap_fields_force_write()

regmap_fields_force_write() is similar to regmap_fields_write(),
but regmap_fields_force_write() write data to register even though
it is same value.

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index e4b9ad4..519c962 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -505,6 +505,8 @@
 
 int regmap_fields_write(struct regmap_field *field, unsigned int id,
 			unsigned int val);
+int regmap_fields_force_write(struct regmap_field *field, unsigned int id,
+			unsigned int val);
 int regmap_fields_read(struct regmap_field *field, unsigned int id,
 		       unsigned int *val);
 int regmap_fields_update_bits(struct regmap_field *field,  unsigned int id,