meson: fix swr KNL build

There's a typo in one of the #defines that breaks compilation.

Fixes: e0b037d6
       ("meson: Build SWR driver")
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109023


Reviewed-by: Eric Engestrom <eric.engestrom@intel.com>
(cherry picked from commit 3ba7ab8d)