dps: do not evaluate a SRC port
dps: do not evaluate a SRC port

If the port is connected to a DRP device, and we are sourcing
the device, do not evaluate it as a power source or we might
sink from the port.

BUG=b:206601685
TEST=Ensure the PDO is not evaluated if the power role is SRC
BRANCH=cherry

Change-Id: Ia70b39d88467b2835f1903ae1c8b0af168688cd8
Signed-off-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3448056
Reviewed-by: Ting Shen <c671d3efec3d7e7e285f3788bf0d1ba4c8605b78@chromium.org>
Tested-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>
Commit-Queue: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec