MIPS: ralink: Don't use "proxy" headers

Update header inclusions to follow IWYU (Include What You Use)
principle.

Fixes: 5804be06 ("MIPS: ralink: Remove unused of_gpio.h")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202403090727.nLhljNp6-lkp@intel.com/Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>

arch/mips/ralink/timer.c

@@ -6,10 +6,16 @@
  * Copyright (C) 2013 John Crispin <john@phrozen.org>
 */
 
-#include <linux/platform_device.h>
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <linux/err.h>
 #include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
 #include <linux/timer.h>
-#include <linux/clk.h>
+#include <linux/types.h>
 
 #include <asm/mach-ralink/ralink_regs.h>