platform/chrome: cros_ec_proto: separate cros_ec_get_proto_info()

Rename cros_ec_host_command_proto_query() to cros_ec_get_proto_info()
and make it responsible for setting `ec_dev` fields according to the
response protocol info.

Also make cros_ec_get_host_event_wake_mask() allocate its own message
buffer.  It was lucky that size of `struct ec_response_host_event_mask`
is less than `struct ec_response_get_protocol_info`.  Thus, the buffer
wasn't overflow.

Reviewed-by: Guenter Roeck <groeck@chromium.org>
Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org>
Link: https://lore.kernel.org/r/20220609084957.3684698-8-tzungbi@kernel.org