reset: Return -ENOTSUPP when not configured

commit 168d7c4e upstream.

Prior to commit 6c96f05c ("reset: Make [of_]reset_control_get[_foo]
functions wrappers"), the "optional" functions returned -ENOTSUPP when
CONFIG_RESET_CONTROLLER was not set.

Revert back to the old behavior by changing the new
__devm_reset_control_get() and __of_reset_control_get() functions to
return ERR_PTR(-ENOTSUPP) when compiled without CONFIG_RESET_CONTROLLER.

Otherwise they will return -EINVAL causing users to think that an error
occurred when CONFIG_RESET_CONTROLLER is not set.

Fixes: 6c96f05c ("reset: Make [of_]reset_control_get[_foo] functions wrappers")
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

include/linux/reset.h

@@ -71,14 +71,14 @@ static inline struct reset_control *__of_reset_control_get(
 					struct device_node *node,
 					const char *id, int index, int shared)
 {
-	return ERR_PTR(-EINVAL);
+	return ERR_PTR(-ENOTSUPP);
 }
 
 static inline struct reset_control *__devm_reset_control_get(
 					struct device *dev,
 					const char *id, int index, int shared)
 {
-	return ERR_PTR(-EINVAL);
+	return ERR_PTR(-ENOTSUPP);
 }
 
 #endif /* CONFIG_RESET_CONTROLLER */