drm/i915: Print plane name in fbc tracepoints

Print the name of the plane in the fbc tracepoints. As the
pipe<->plane assignment can vary on old hw it's probably
more helpful to see both the plane and the pipe names together.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221111123120.7759-3-ville.syrjala@linux.intel.com
Acked-by: Jani Nikula <jani.nikula@intel.com>