meson: dri-drivers-path as option is a full path

Meson-options stays that 'dri-drivers-path' is a location to install dri drivers. Postfix '-path' seems to be treated as a full path and not related to option 'prefix'. By default path will be constructed as prefix/libdir/dri, otherwise a full path has to be provided as option.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=109698 CC: Rafael Antognolli rafael.antognolli@intel.com CC: Dylan Baker dylan@pnwbakers.com Fixes: 306914db (meson: Add dridriverdir variable to dri.pc.) Signed-off-by: Sergii Romantsov sergii.romantsov@globallogic.com