drm/komeda: Mark the local functions as static

Fix the kbuild test rebot reported warnings:
- symbol was not declared. Should it be static?
- missing braces around initializer

Depends on:
- https://patchwork.freedesktop.org/series/58976/

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: james qian wang (Arm Technology China) <james.qian.wang@arm.com>
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>