x86/platform/uv: Fix indentation warning in Documentation/ABI/testing/sysfs-firmware-sgi_uv

Commit

  c9624cb7 ("x86/platform/uv: Update sysfs documentation")

misplaced the first line of a codeblock section, causing the reported
warning message:

  Documentation/ABI/testing/sysfs-firmware-sgi_uv:2: WARNING: Unexpected indentation.

Move the misplaced line below the required blank line to remove the
warning message.

Fixes: c9624cb7 ("x86/platform/uv: Update sysfs documentation")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Justin Ernst <justin.ernst@hpe.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Mike Travis <mike.travis@hpe.com>
Link: https://lkml.kernel.org/r/20210219182852.385297-1-justin.ernst@hpe.com