buildroot: fix for build on Ubuntu 22.04 LTS

Build failure fixed:

/usr/include/features-time64.h:26:5: error: #error "_TIME_BITS=64 is allowed only with _FILE_OFFSET_BITS=64"
   26 | #   error "_TIME_BITS=64 is allowed only with _FILE_OFFSET_BITS=64"

Fixes: #306

Signed-off-by: Christian Stewart <christian@aperture.us>