ACPI / Kconfig: Remove redundant depends on ACPI

Since config ACPI_REDUCED_HARDWARE_ONLY is already depended
on ACPI (inside if ACPI / endif), so depdens on ACPI is redundant,
remove it and fix the minor syntax problem also.

Signed-off-by: Hanjun Guo <hanjun.guo@linaro.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>