linux-phytec-ti

test_power: Add support for USB AC source

Usually a device has both AC plug and UDC plug usable for charging.
Provide both AC sources.

Signed-off-by: Dmitry Eremin-Solenikov <dmitry_eremin@mentor.com>
Signed-off-by: Anton Vorontsov <cbouatmailru@gmail.com>