drm/bridge: megachips-stdpxxxx-ge-b850v3-fw: switch to drm_do_get_edid()

Migrate away from custom EDID parsing and validity checks.

Note:  This is a follow-up to the original RFC by Jani [1].  The first
submission in this series should have been marked v2.

[1] https://patchwork.freedesktop.org/patch/msgid/20230901102400.552254-1-jani.nikula@intel.com



Co-developed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ian Ray <ian.ray@ge.com>
Reviewed-by: Robert Foss <rfoss@kernel.org>
Signed-off-by: Robert Foss <rfoss@kernel.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230921104751.56544-1-ian.ray@ge.com