ARM: msm: vreg is a module and so needs module.h

The MSM7201 vreg appears to have gotten missed in the module.h
cleanup.

Signed-off-by: David Brown <davidb@codeaurora.org>

arch/arm/mach-msm/vreg.c

@@ -19,6 +19,7 @@
 #include <linux/device.h>
 #include <linux/init.h>
 #include <linux/debugfs.h>
+#include <linux/module.h>
 #include <linux/string.h>
 #include <mach/vreg.h>