regulator: Constify constraints name

There's no need for the API to modify it and having it const makes it
easier to use with random strings the board code has.

Change-Id: Icd7e600291f281e80f60ef857c22f22cba08bfc1
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
[mbohan: port MSM regulator drivers to new const type]
Signed-off-by: Michael Bohan <mbohan@codeaurora.org>
diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/machine.h
index 6804ef3..22a832a 100644
--- a/include/linux/regulator/machine.h
+++ b/include/linux/regulator/machine.h
@@ -95,7 +95,7 @@
  */
 struct regulation_constraints {
 
-	char *name;
+	const char *name;
 
 	/* voltage output range (inclusive) - for voltage control */
 	int min_uV;