drm: Fix some coding style issues

Put an empty line between the variable declarations and the code, and
use tabs for alignment.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180305144919.2881-3-ville.syrjala@linux.intel.com


Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>