power: smblib: SW implementation of typeC try.SNK

Try.SNK allows a DRP that has a policy based preference to be a Sink
when connecting to another DRP to effect a transition from a destined
Source role to the Sink role.

This is a Software implementation for PMI8998.

Exiting from AttachWait.SRC State, a DRP that strongly prefers the
Sink role may optionally transition to Try.SNK instead of Attached.SRC.

When in the Try.SNK state, the port is querying to determine if the
port partner supports the Source role.

The port shall then transition to Attached.SNK when the SNK.Rp state
is detected for at least tTryCCDebounce and VBUS is detected

Alternatively, the port shall transition to TryWait.SRC if SNK.Rp state
is not detected tTryCCDebounce.

The port shall transition to Attached.SRC when SRC.Rd state is detected
on exactly one of the CC pins.

The port shall transition to Unattached.SNK after tDRPTry if neither of
the CC1 or CC2 pins is in the SRC.Rd state.

CRs-Fixed: 1114313
Change-Id: I777332e87df65082333f4e24a61c5ea834784d09
Signed-off-by: Harry Yang <harryy@codeaurora.org>