clk: msm: clock-cpu-8996: Don't try to unmap bases in probe

We're trying to be a little too clever in the probe
function by trying to unmap the APC0/1 base if it
has already been mapped before probe. However there
is no necessity to do this; the memory mapping code
is optimized enough that it won't return a new mapping
for the same physical space. Furthermore, probe deferral
and devm_ioremap results in unmapping of the memory with
the pointers still pointing to the mapping, triggering
a warning on the next probe attempt.

Don't try to unmap the memory during probe.

Change-Id: I55b89224c155d33ffad0c0729c6e69381a83a316
Signed-off-by: Vikram Mulukutla <markivx@codeaurora.org>