drm/i915: include linux/highmem.h and linux/swap.h where needed

Include linux/highmem.h and linux/swap.h explicitly where needed so we
can drop the linux/i2c.h include from i915_drv.h where it pulled in the
dependencies implicitly.

Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220303181931.1661767-5-jani.nikula@intel.com
diff --git a/drivers/gpu/drm/i915/i915_cmd_parser.c b/drivers/gpu/drm/i915/i915_cmd_parser.c
index 5f6e416..f93e612 100644
--- a/drivers/gpu/drm/i915/i915_cmd_parser.c
+++ b/drivers/gpu/drm/i915/i915_cmd_parser.c
@@ -25,6 +25,8 @@
  *
  */
 
+#include <linux/highmem.h>
+
 #include <drm/drm_cache.h>
 
 #include "gt/intel_engine.h"