tcpci: remove vbus level caching
tcpci: remove vbus level caching

On yorp, the PS8751 TCPC resets its event mask when it goes into low
power mode which turns off the VBUS detection event mask. Since the
first interrupts after lower power mode should contain the vbus
changed interrupt we miss it.

We have tried many different permutations of resetting the event mask
on reset without achieving 100% detection success.

The PPC Vbus detection code calls out to the PPC over i2c every time
vbus level is checked; applying that strategy for TPCPs make the
detection much more robust.

BRANCH=none
BUG=b:77458917
TEST=yorp detect vbus on insertion every time with PS8751

Change-Id: I15b5f2ee016f68bac9e4bf4d5d89bbaef323f131
Signed-off-by: Jett Rink <9d4aef0593e6843318d99df31597fb6153b89787@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/993394
Reviewed-by: Scott Collyer <7d40b3eb9e17bf55d972074a5e77a7ea4159f9dd@chromium.org>

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