smb-lib: ignore disconnects during power role swap

During a power_role swap, the CC lines get disconnected for a bit.
This causes the charger driver to prematurely declare a disconnection
and it resets back to disconnected state.

Update the code to distinguish a disconnect caused during PR_SWAP vs
a real disconnect.
Avoid
- resetting the CC line to HW control
- switching DRP mode
- enabling the crude sensor workaround
- enabling APSD
during a discconnet caused by PR_SWAP

Note that PR_SWAP setting/unsetting needs to done regardless of the
connected state of the CC line. When PR_SWAP is notified to be
completed and the CC lines are still seen disconnected call the real
disconnect code.

While at it Vconn can be disabled too in the real disconnect code path.

Change-Id: I97ab7ee343c5b2bcf25797e6acbb1de37f5ba00a
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>