drm/amdgpu: ensure all userq VAs mapped before restore

drm/amdgpu: ensure all userq VAs mapped before restore

amdgpu_userq_buffer_vas_mapped() checks whether all VAs
of a queue are mapped before restoring it.
So that HW won't access any invalid addresses.

Currently, this function assumes all VAs are mapped if
any VA of a queue has been mapped, which is wrong.

This commit fixes this problem by examining all VAs of
a queue and reporting false if any of them is not mapped.

Signed-off-by: Zhu Lingshan <lingshan.zhu@amd.com>
Reviewed-by: Sunil Khatri <sunil.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>