ASoC: qcom: restore documentation for device tree binding

While porting support for MSM8952, the device tree binding
documentation for latest qcom chipsets got overwritten by
documentation for older chipsets. Revert those changes and
keep MSM8952 binding information.

Change-Id: I393a7740b067adfef80c558ef279baa81499ce1d
Signed-off-by: Banajit Goswami <bgoswami@codeaurora.org>