net: cnss: add snapshot of cnss platform driver

This is a snapshot of the CNSS driver and associated files as of
msm-4.14 commit b56fde2f9abd44
("cnss: Add cnss driver to msm-4.14").

Add Kconfig dependency.
Comment obsolete codes to fix some compiler issues.

Change-Id: I89bf0a85b086c7482609b331273d9eaf2fb66648
Signed-off-by: Paul Zhang <paulz@codeaurora.org>