ASoC: wcd: fix issues in extension cable

Prevent false button press on removal of headset from
the extension cable by cancelling the work in the
removal handler. If PA is enabled by dapm while we
enable schmitt trigger, it can cause continuous
electrical insertion interrupts from HPHL. To avoid
this make sure the PA's are off before enabling schmitt
trigger. Do not touch button press interrupt flag anywhere.

Change-Id: I9793af29f6580b9f5ab6d9f602cdcd156cb8dce8
Signed-off-by: Simmi Pateriya <simmip@codeaurora.org>
Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>