Documentation: ACPI: fix error script name

The correct script name should be 'divergence.sh' instead of
'divergences.sh'.
I didn't find divergences.sh in the path of acpica/generate/linux/.
Signed-off-by: Hao Chen <chenhaoa@uniontech.com>
Link: https://lore.kernel.org/r/20210617023300.30114-1-chenhaoa@uniontech.comSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/driver-api/acpi/linuxized-acpica.rst

@@ -276,4 +276,4 @@ before they become available from the ACPICA release process.
    # git clone https://github.com/acpica/acpica
    # git clone https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
    # cd acpica
-   # generate/linux/divergences.sh -s ../linux
+   # generate/linux/divergence.sh -s ../linux