platform_data/mlxreg: Add support for complex attributes

Add new field 'regnum' to the structure 'mlxreg_core_data' to specify
the number of registers occupied by multi-register attribute.
Signed-off-by: Vadim Pasternak <vadimp@mellanox.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

include/linux/platform_data/mlxreg.h

@@ -80,6 +80,7 @@ struct mlxreg_hotplug_device {
  * @hpdev - hotplug device data;
  * @health_cntr: dynamic device health indication counter;
  * @attached: true if device has been attached after good health indication;
+ * @regnum: number of registers occupied by multi-register attribute;
  */
 struct mlxreg_core_data {
 	char label[MLXREG_CORE_LABEL_MAX_SIZE];
@@ -92,6 +93,7 @@ struct mlxreg_core_data {
 	struct mlxreg_hotplug_device hpdev;
 	u8 health_cntr;
 	bool attached;
+	u8 regnum;
 };
 
 /**