ASoC: wcd: toggle FSM during polling

If headset is slowly connected, some times it is getting
detected as headphone.To avoid this scenario, toggle
FSM during polling period. Toggeling FSM results
in button press if cable is headphone, no change in
state if cable is headset.

CRs-Fixed: 787909
Change-Id: I169523deee3d81f9a0cc271f11ec3b51f543a41e
Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>