regulator: core: Allow fixed enable_time to be set in the regulator_desc

Many regulators have a fixed specification for their enable time. Allow
this to be set in the regulator_desc as a number to save them having to
implement an explicit operation.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
diff --git a/include/linux/regulator/driver.h b/include/linux/regulator/driver.h
index 84f999ed..176bd43 100644
--- a/include/linux/regulator/driver.h
+++ b/include/linux/regulator/driver.h
@@ -180,6 +180,8 @@
  * @vsel_mask: Mask for register bitfield used for selector
  * @enable_reg: Register for control when using regmap enable/disable ops
  * @enable_mask: Mask for control when using regmap enable/disable ops
+ *
+ * @enable_time: Time taken for initial enable of regulator (in uS).
  */
 struct regulator_desc {
 	const char *name;
@@ -201,6 +203,8 @@
 	unsigned int vsel_mask;
 	unsigned int enable_reg;
 	unsigned int enable_mask;
+
+	unsigned int enable_time;
 };
 
 /**