drm/i915: Separate sideband declarations to intel_sideband.h

Split the sideback declarations out of the ginormous i915_drv.h

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190426081725.31217-5-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index 5d4a793..4b763c2 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -38,6 +38,7 @@
 #include "intel_fbc.h"
 #include "intel_pm.h"
 #include "intel_sprite.h"
+#include "intel_sideband.h"
 #include "../../../platform/x86/intel_ips.h"
 
 /**