drm/i915: Add I2C and DP-AUX char devices to debug kconfig

These char devices exposing the driver's I2C and DP-AUX adapters for
user space tools are useful to debug display output related issues.
Enable them with the rest of additional driver debug options.
Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1480696541-13697-1-git-send-email-imre.deak@intel.com

drivers/gpu/drm/i915/Kconfig.debug

@@ -19,6 +19,8 @@ config DRM_I915_DEBUG
         bool "Enable additional driver debugging"
         depends on DRM_I915
         select PREEMPT_COUNT
+        select I2C_CHARDEV
+        select DRM_DP_AUX_CHARDEV
         select X86_MSR # used by igt/pm_rpm
         select DRM_VGEM # used by igt/prime_vgem (dmabuf interop checks)
         select DRM_DEBUG_MM if DRM=y