PM: rwsem.h need not be included into main.c

It is not necessary to include <linux/rwsem.h> into
drivers/base/power/main.c, so don't do that.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

drivers/base/power/main.c

@@ -23,7 +23,6 @@
 #include <linux/pm.h>
 #include <linux/pm_runtime.h>
 #include <linux/resume-trace.h>
-#include <linux/rwsem.h>
 #include <linux/interrupt.h>
 #include <linux/sched.h>