clk: qcom: clk-dummy: Add a dummy clock provider

Add a dummy clock provider that registers a simple callback that
in turn always returns the dummy clock for any clk_get call.

In addition, consumers of the dummy clock provider would require
support for dummy resets, which would make a dummy assert/deassert
of the reset signals.

Change-Id: I08fcb174fd0e0c49f8069e106b48597bcdfe847d
Signed-off-by: Taniya Das <tdas@codeaurora.org>
Signed-off-by: Deepak Katragadda <dkatraga@codeaurora.org>