coresight: place pm_runtime_put() properly

When we register coresight device to the amba bus, before calling
driver probe, clocks will be enabled by the amba bus framework and
disabled only in failure cases returned by driver probe. So, ensure not
to call the pm_runtime_put, which also disables the clocks, in probe
failure cases. Otherwise clocks gets disabled twice, once by amba bus
framework and then by the pm_runtime_put, that leads to the loss of
the clock vote by the previous coresight module, if any.

Change-Id: Ied492303458ad12acb65bf2e80fb30efc5fee837
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>