msm: clock-krait-8974: Add support for DT clock lookup

Register the clock-krait driver as the provider of the
krait clocks and introduce the of_index values for krait
clocks so that the clock clients can use the DT clock lookup
features.

Note that this change also provides the backward compatibility
for table based lookup.

Change-Id: I104385269d2d9b989171a9ea7722e3ba4293d09f
Signed-off-by: Tianyi Gou <tgou@codeaurora.org>