cpufreq: highbank: fix ARM_HIGHBANK_CPUFREQ dependency warning

When make ARCH=arm multi_v7_defconfig, we get the following warnings:

warning: (ARM_HIGHBANK_CPUFREQ) selects GENERIC_CPUFREQ_CPU0 which has
unmet direct dependencies (ARCH_HAS_CPUFREQ && CPU_FREQ && HAVE_CLK
&& REGULATOR && OF && THERMAL && CPU_THERMAL)

To fix this, make ARM_HIGHBANK_CPUFREQ depend on ARCH_HAS_CPUFREQ and
REGULATOR instead of selecting them, PM_OPP will be selected by ARCH_HAS_CPUFREQ.

Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>