cpufreq: qcom-cpufreq-hw: Fix incorrect type warning from sparse

The implicit typecast from void * to __iomem cause sparse to complain
about incorrect type in initializer, so fix the same.

Change-Id: I9690d76a9991667496011894f0a1fd83a7e23c1f
Signed-off-by: Naveen Yadav <naveenky@codeaurora.org>