ASoC: jack: Fix buttons enum value

Microphone2 and SND_JACK_BTN_5 enum are same, resulting
in SND_JACK_BTN_5 event getting triggered when ANC headset
is plugged into the device. Use unique values in
sound jack type enum.

Change-Id: I668e50afcad11b1f62f511f4241f79bad858c7d2
Signed-off-by: Sudheer Papothi <spapothi@codeaurora.org>