tests/meson.build: disable nouveau tests for static build

Signed-off-by: Peter Seiderer ps.report@gmx.net

Notes:

• the existing test/check for static build in meson.build does not catch this case because e.g. the buildroot toolchain br-arm-full-static-2019.05.1 provides an empty libdl.a

  169 # Among others FreeBSD does not have a separate dl library.
  170 if not cc.has_function('dlsym')
  171   dep_dl = cc.find_library('dl', required : with_nouveau)
  172 else
  173   dep_dl = []
  174 endif

Changes v1 -> v2:

• re-based on master
• re-opened new merge request as original one !29 (closed) was closed/patch was squased into merge request !28 (closed) which was declined, but similar/same was merged later with !139 (merged) (commit 52f05d3d), so re-send this remaining fix as new merge request