media: dt-bindings: media: add new rc map names

Add new entries for linux,rc-map-name:
- rc-khadas
- rc-odroid
- rc-tanix-tx3mini
- rc-wetek-hub
- rc-wetek-play2
- rc-x96max

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Rob Herring <robh@kernel.org>