pd: reject getSourceCap/getSinkCap if doesn't apply
pd: reject getSourceCap/getSinkCap if doesn't apply

Send a reject to getSourceCap if device is only a Sink.
Send a reject to getSinkCap if device is only a Source.

BUG=chrome-os-partner:34979
BRANCH=samus
TEST=make -j buildall

Change-Id: I53711fd88235c1c98d40fa2c59d48306e9ee7ba2
Signed-off-by: Alec Berg <1a4429eeda29095a12e19a73405f80f5b7f37a63@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/238231
Reviewed-by: Vincent Palatin <70a9964ec8fd10b0b08fcc8623c2add25ddf99ac@chromium.org>
(cherry picked from commit 017f151ea36a3309aec05ace79916ab3dae35ac1)
Signed-off-by: Alec Berg <1a4429eeda29095a12e19a73405f80f5b7f37a63@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/238606

thehobn/ec,thehobn/ec,thehobn/ec,thehobn/ec