dt-bindings: connector: Add child nodes for multiple PD capabilities

Commit 662a6010

 ("usb: typec: Separate USB Power Delivery from USB
Type-C") allows userspace to configure the PD of a port by selecting
different set of predefined PD capabilities. Define the PD capability
sets in DT for better configurability in device modules.

Define an optional child node "capabilities" to contain multiple USB
Power Delivery capabilities.

Define child nodes with pattern (e.g. caps-0, caps-1) under
"capabilities". Each node contains PDO data of a selectable Power
Delivery capability.

Also define common properties for source-pdos, sink-pdos, and
op-sink-microwatt that can be referenced.

Signed-off-by: Kyle Tso <kyletso@google.com>
Link: https://lore.kernel.org/r/20231205030114.1349089-2-kyletso@google.com
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20231216104630.2720818-2-kyletso@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>