drm/edid: avoid drm_edid_find_extension() internally

Prefer the EDID iterators over drm_edid_find_extension() in
drm_edid_has_cta_extension(), even if this leads to more code. The key
is to use the same patterns as much as possible.

Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/9fa366147b06a28304527be48f1b363c3484c8a3.1713259151.git.jani.nikula@intel.com


Signed-off-by: Jani Nikula <jani.nikula@intel.com>