board: 8974: Add SDCC3 gpio mux information for APQ8074 devices

There are two different WLAN architectures used in the QCOM 8x74 platforms:
WCNSS and QCA6234. WCNSS uses default configuration for MSM GPIOs 35-40.
QCA6234 uses alternative configuration (the GPIOs are used as SDCC3 data
lines).
The aim of this patch is to make the alternative configuration depend
on runtime platform detection. The previous implementaion was inaccurate,
because it used the SDC3 featurization flag for functionality selection.
In the new implementation the same code will run on both
WCNSS and QCA6234 equipped platforms.

Change-Id: I2f5c8dfd82a8f956e7b5f054b652bfa0150dc23d
Signed-off-by: Ilia Lin <ilialin@codeaurora.org>