ASoC: wcd: Do not enable pulldown when headset is inserted

If pulldown is enabled when headset is inserted, issues
such as no button press or fake interrupts during extension
cable usecase are seen. Do not enable pulldown when headset
is kept inserted.

Change-Id: I586376a806e8f3495fc94b7a8f4af62a59f17bbe
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>