drm/i915/display: include i915_gpu_error.h where needed

Include what you use. With this, we can drop the include from xe compat
i915_drv.h.
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/a5dbb8d46403761bd8518db45fa71dc55930d3cf.1717004739.git.jani.nikula@intel.com

drivers/gpu/drm/i915/display/intel_dmc.c

@@ -26,6 +26,7 @@
 #include <linux/firmware.h>
 
 #include "i915_drv.h"
+#include "i915_gpu_error.h"
 #include "i915_reg.h"
 #include "intel_de.h"
 #include "intel_dmc.h"

drivers/gpu/drm/xe/compat-i915-headers/i915_drv.h

@@ -19,7 +19,6 @@
 #include "xe_bo.h"
 #include "xe_pm.h"
 #include "xe_step.h"
-#include "i915_gpu_error.h"
 #include "i915_reg_defs.h"
 #include "i915_utils.h"
 #include "intel_step.h"