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.

CRs-Fixed: 982110
Change-Id: Ia7e9f427dc20bbc0db61a1bc2debbe4536066cc0
Signed-off-by: Yeleswarapu Nagaradhesh <nagaradh@codeaurora.org>