ASoC: msm8996: Fix kernel crash in "Speaker Function" mixer control

Use snd_soc_kcontrol_codec instead of snd_kcontrol_chip
to obtain the codec information from the kcontrol.

CRs-Fixed: 1099607
Change-Id: Iba3004c2745e5f0bbe778e44c803826351b3b939
Signed-off-by: Aditya Bavanari <abavanar@codeaurora.org>