dt-bindings: soc: ti: Convert ti,sci-pm-domain to json schema

Convert the ti,sci-pm-domain to json schema for better checks and
documentation.

Differences being:
 - Drop consumer example as they are documented in the corresponding
   bindings themselves.
 - Drop phandle description for reset consumer or cell definition as it
   is redundant.

Signed-off-by: Nishanth Menon <nm@ti.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Tero Kristo <kristo@kernel.org>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20210426155457.21221-4-nm@ti.com


Signed-off-by: Rob Herring <robh@kernel.org>