net: dsa: hellcreek: Replace kernel.h with what is used

kernel.h is included solely for some other existing headers.
Include them directly and get rid of kernel.h.

While at it, sort headers alphabetically for easier maintenance.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/dsa/hirschmann/hellcreek.h

@@ -12,14 +12,16 @@
 
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
+#include <linux/container_of.h>
 #include <linux/device.h>
-#include <linux/kernel.h>
-#include <linux/mutex.h>
-#include <linux/workqueue.h>
 #include <linux/leds.h>
+#include <linux/mutex.h>
 #include <linux/platform_data/hirschmann-hellcreek.h>
 #include <linux/ptp_clock_kernel.h>
 #include <linux/timecounter.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+
 #include <net/dsa.h>
 #include <net/pkt_sched.h>