dps: reset PD voltage when dps disabled.
dps: reset PD voltage when dps disabled.

To enforce the PD voltage back to the default value, we have
to force a new request.

BUG=b:169532537
TEST=dps dis, and a new PD request is issued
BRANCH=asurada

Change-Id: I4c7d1d6019a9095099dc992411890e394c71b820
Signed-off-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3229048
Reviewed-by: Aseda Aboagye <12c9b286316a940fd31c24070da5ab64cdd4d0e7@chromium.org>
Commit-Queue: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>
Tested-by: Eric Yilun Lin <2f2733c7206ea2b76bd2db1905cc5e8a75841c48@google.com>

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