ASoC: wcd: correct handling of GND_MIC_SWAP type detection

In current hardware MBHC, if there is no gpio setting for swap
switch and we insert a EURO headset into a US jack, it will be
detected as HEADSET finally. Make the change to set the plug
type as GND_MIC_SWAP when the swap counter reaches
GND_MIC_SWAP_THRESHOLD.

CRs-Fixed: 793061
Change-Id: I74cc80343f466367b03d7c7fabefe1009fa08727
Signed-off-by: Walter Yang <yandongy@codeaurora.org>