x86: qemu: Drop our own ACPI implementation

x86: qemu: Drop our own ACPI implementation

Our own ACPI implementation (when CONFIG_QEMU_ACPI_TABLE is not set)
does not build anymore after x86 has been fully converted to DM PCI.
Instead of trying to fix the build errors, given we now have the ACPI
support via QEMU's fw_cfg interface, which is a more reliable way to
generate correct ACPI tables than by ourselves, hence drop our own
ACPI implementation.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>