drm/ttm/tests: Add tests for ttm_device

Test initialization and cleanup of the ttm_device struct, including
some error paths. Verify the creation of page pools if use_dma_alloc
param is true.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/2abb0e53e7d56b0a24d0255f9075e2123b991278.1691487006.git.karolina.stolarek@intel.com


Signed-off-by: Christian König <christian.koenig@amd.com>