amdgpu/test: Allow BO mapping flags to be passed in tests

v2:
Call amdgpu_bo_va_op_raw directly in amdgpu_bo_alloc_and_map_raw
Move amdgpu_bo_alloc_and_map_raw into C file to avoid including
unistd.h in amdgpu_test.h

Signed-off-by: Andrey Grodzovsky <andrey.grodzovsky@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>