thermal: remove unnecessary include

No need for spinlocks in this file, then removing its header.
Signed-off-by: Eduardo Valentin <eduardo.valentin@ti.com>
Reviewed-by: Durgadoss R <durgadoss.r@intel.com>
Signed-off-by: Zhang Rui <rui.zhang@intel.com>

drivers/thermal/thermal_sys.c

@@ -32,7 +32,6 @@
 #include <linux/kdev_t.h>
 #include <linux/idr.h>
 #include <linux/thermal.h>
-#include <linux/spinlock.h>
 #include <linux/reboot.h>
 #include <net/netlink.h>
 #include <net/genetlink.h>