drm/i915: make intel_uc_fw.h self-contained

Add the minimal includes/declarations to make the header self-contained,
and ensure it stays that way.
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190626144020.2155-13-jani.nikula@intel.com

drivers/gpu/drm/i915/Makefile.header-test

@@ -26,6 +26,7 @@ header_test := \
 	intel_pm.h \
 	intel_runtime_pm.h \
 	intel_sideband.h \
+	intel_uc_fw.h \
 	intel_uncore.h \
 	intel_wakeref.h
 

drivers/gpu/drm/i915/intel_uc_fw.h

@@ -25,6 +25,8 @@
 #ifndef _INTEL_UC_FW_H_
 #define _INTEL_UC_FW_H_
 
+#include <linux/types.h>
+
 struct drm_printer;
 struct drm_i915_private;