drm/connector: Add TV standard property

The TV mode property has been around for a while now to select and get the
current TV mode output on an analog TV connector.

Despite that property name being generic, its content isn't and has been
driver-specific which makes it hard to build any generic behaviour on top
of it, both in kernel and user-space.

Let's create a new enum tv norm property, that can contain any of the
analog TV standards currently supported by kernel drivers. Each driver can
then pass in a bitmask of the modes it supports, and the property
creation function will filter out the modes not supported.

We'll then be able to phase out the older tv mode property.

Tested-by: Mateusz Kwiatkowski <kfyatek+publicgit@gmail.com>
Acked-in-principle-or-something-like-that-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: https://lore.kernel.org/r/20220728-rpi-analog-tv-properties-v10-5-256dad125326@cerno.tech


Signed-off-by: Maxime Ripard <maxime@cerno.tech>