ACPI reduced hardware mode is disabled by default, but ARM64
can only run properly in ACPI hardware reduced mode, so select
ACPI_REDUCED_HARDWARE_ONLY if ACPI is enabled on ARM64.

If the firmware is not using hardware reduced ACPI mode, we
will disable ACPI to avoid nightmare such as accessing some
registers which are not available on ARM64.

CC: Catalin Marinas <catalin.marinas@arm.com>
CC: Will Deacon <will.deacon@arm.com>
Reviewed-by: NGrant Likely <grant.likely@linaro.org>
Tested-by: NSuravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Tested-by: NYijing Wang <wangyijing@huawei.com>
Tested-by: NMark Langsdorf <mlangsdo@redhat.com>
Tested-by: NJon Masters <jcm@redhat.com>
Tested-by: NTimur Tabi <timur@codeaurora.org>
Tested-by: NRobert Richter <rrichter@cavium.com>
Acked-by: NRobert Richter <rrichter@cavium.com>
Signed-off-by: NAl Stone <al.stone@linaro.org>
Signed-off-by: NHanjun Guo <hanjun.guo@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>