msm: 8960: Configure GPIO 23 as External VFR for SGLTE platforms

Impact:
GPIO 23 should be configured to act as an External VFR for Q6.

Problem:
In SGLTE Fusion targets, when QSC call is active, there is no VFR
which drives Q6 to deliver voice packets to Modem.

Change:
Configure GPIO 23 to act as an external VFR to Q6 to drive the
voice packet delivery to Modem.

Change-Id: I36e2982ca5bc9ed9050ec9ad50f3ba95551bcd08
Signed-off-by: Satish Babu Patakokila <sbpata@codeaurora.org>