drm/print: Move kerneldoc next to definition

drm/print: Move kerneldoc next to definition

kerneldoc expects the comment next to definitions, otherwise it can't
pick up exported vs. internal stuff.

This fixes a warning from the doc build done with:

$ make DOCBOOKS="" htmldocs

Fixes: d8187177b0b1 ("drm: add helper for printing to log or seq_file")
Cc: Rob Clark <[email protected]>
Cc: Sean Paul <[email protected]>
Reviewed-by: Chris Wilson <[email protected]>
Signed-off-by: Daniel Vetter <[email protected]>
Link: http://patchwork.freedesktop.org/patch/msgid/[email protected]