it5205: put ite5202 mux into low power mode
it5205: put ite5202 mux into low power mode

When the SS MUX is fully disconnected, put the mux into a low power
state.

BRANCH=none
BUG=b:111006203,b:111520593
TEST=BIP PD_A rail went from 3.97mW down to 2.65 mW during hibernate
with the other corresponding PPC changes in CL:1166184

Change-Id: Ief636b569fe01db7f129ca2d457352c3799c14f9
Signed-off-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/1169698
Reviewed-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>
Reviewed-by: Furquan Shaikh <6be5c96c464778f89679b1062a2e0a6af93d2aa5@chromium.org>

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