configs: qemu: add config fragment for ACPI

Provide a configuration fragment to enable ACPI on QEMU.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/doc/board/emulation/acpi.rst b/doc/board/emulation/acpi.rst
new file mode 100644
index 0000000..17b68e1
--- /dev/null
+++ b/doc/board/emulation/acpi.rst
@@ -0,0 +1,23 @@
+.. SPDX-License-Identifier: GPL-2.0+
+
+ACPI on QEMU
+============
+
+QEMU can provide ACPI tables on ARM, RISC-V (since QEMU v8.0.0), and x86.
+
+The following U-Boot settings are needed for ACPI support::
+
+    CONFIG_CMD_QFW=y
+    CONFIG_ACPI=y
+    CONFIG_GENERATE_ACPI_TABLE=y
+
+On x86 these settings are already included in the defconfig files. ARM and
+RISC-V default to use device-trees.
+
+Instead of updating the configuration manually you can add the configuration
+fragment `acpi.config` to the make command for initializing the configuration.
+E.g.
+
+.. code-block:: bash
+
+    make qemu-riscv64_smode_defconfig acpi.config
diff --git a/doc/board/emulation/index.rst b/doc/board/emulation/index.rst
index 932c65a..d3d6b8f 100644
--- a/doc/board/emulation/index.rst
+++ b/doc/board/emulation/index.rst
@@ -6,6 +6,7 @@
 .. toctree::
    :maxdepth: 1
 
+   acpi
    blkdev
    ../../usage/semihosting
    qemu-arm