power: supply: charger-manager: Update extcon functions

In commit 830ae442 ("extcon: Remove the deprecated extcon functions")
the function extcon_register_interest became a no-op returning an error,
leading to non-functional behaviour in charger-manager.

Additionally, a translation table is needed between the text representation
of the extcon cable names and their IDs is needed.  In order to retain DT
compatibility, TA and CHARGE-DOWNSTREAM are added as they were present up
until commit 11eecf91 ("extcon: Modify the id and name of external
connector")

Signed-off-by: Jonathan Bakker <xc-racer2@live.ca>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>