drm/i915: Move MST master transcoder dump earlier

Move the MST master transcoder dump next to the other transcoder
bits.

Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200925131656.10022-3-ville.syrjala@linux.intel.com