PM / OPP: Rename routines specific to old bindings with _v1

Clearly distinguish routines based on what version of bindings they
parse. We have already postfixed routines properly with _v2 for new
bindings. Postfix the older ones now with _v1.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>