HDMI 2.1 section 10.3.6 defines an HDMI Forum EDID Extension Override
Data Block, which may contain a different extension count than the base
block claims. Add support for reading more EDID data if available. The
extra blocks aren't parsed yet, though.

Hard-coding the EEODB parsing instead of using the iterators we have is
a bit of a bummer, but we have to be able to do this on a partially
allocated EDID while reading it.

v2:
- Check for CEA Data Block Collection size (Ville)
- Amend commit message and comment about hard-coded parsing
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/57b57a355d62eb91ad1e3cf555978576f2bd9fdd.1656494768.git.jani.nikula@intel.com