ASoC: wcd-mbhc: Fix plug removal detection from extension cable

Fix plug removal detection by enabling electrical removal
irq when headset/headphone accessory is removed from the
other end of extension cable.

Change-Id: I585a81e6c01b4ddd249f76614fb933beea3755fc
Signed-off-by: Phani Kumar Uppalapati <phaniu@codeaurora.org>