Validates BO size against each requested domain's total memory.

v2:
Make GTT size check a MUST to allow fall back to GTT.
Rmove redundant NULL check.
Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>