drm/ttm/tests: Add tests for ttm_bo functions

Test reservation and release of TTM buffer objects. Add tests to check
pin and unpin operations.

Signed-off-by: Karolina Stolarek <karolina.stolarek@intel.com>
Tested-by: Amaranath Somalapuram <Amaranath.Somalapuram@amd.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/fcd53970f55ae4be8c738e03f9fcf45366d20b47.1701257386.git.karolina.stolarek@intel.com


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