cpufreq: scmi: Fix build for !CONFIG_COMMON_CLK

cpufreq: scmi: Fix build for !CONFIG_COMMON_CLK

Commit 8410e7f3b31e ("cpufreq: scmi: Fix OPP addition failure with a
dummy clock provider") registers a dummy clock provider using
devm_of_clk_add_hw_provider. These *_hw_provider functions are defined
only when CONFIG_COMMON_CLK=y. One possible fix is to add the Kconfig
dependency, but since we plan to move away from the clock dependency
for scmi cpufreq, it is preferrable to avoid that.

Let us just conditionally compile out the offending call to
devm_of_clk_add_hw_provider. It also uses the variable 'dev' outside
of the #ifdef block to avoid build warning.

Fixes: 8410e7f3b31e ("cpufreq: scmi: Fix OPP addition failure with a dummy clock provider")
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>