ARM: dts: msm: update pinctrl configuration of SSMUX gpio for msmtitanium

MSM gpio controlling SSMUX should be configured with default 'gpio'
function. Update pinctrl devicetree configuration to reflect the same.

Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
Change-Id: Id4aeee0a95483a0ffaf5e68c55aa5af5b2bf27ea