x86: tangier: Enable ACPI support for Intel Tangier

Intel Tangier SoC is a part of Intel Merrifield platform which doesn't
utilize ACPI by default. Here is an attempt to unleash ACPI flexibility
power on Intel Merrifield based platforms.

The change brings minimum support of the devices that found on
Intel Merrifield based end user device.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>