cpufreq: qcom: Add code to support module removal

Support module remove and cleanup of the OPP table entries. In the case
where the driver registers for IRQ, free the IRQ and also remove the
sysfs.

Change-Id: I090a6e6fbcce4578e186fb8bc33cd68de42b34d8
Signed-off-by: Taniya Das <tdas@codeaurora.org>