tools/power/x86/intel-speed-select: Fix mailbox usage for CLOS_PM_QOS_CONFIG

Even for the products using MMIO, this message needs to be sent via
mail box. The previous fix done for this didn't properly address this.
That fix simply removed sending command via MMIO, but still didn't
trigger sending via mailbox.

Add additional condition to check for CLOS_PM_QOS_CONFIG, when MMIO
is supported on a platform.

Fixes: cd0e6370 (tools/power/x86/intel-speed-select: Use mailbox for CLOS_PM_QOS_CONFIG)
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>