drm/amdgpu: Increase KIQ invalidate_tlbs timeout

KIQ invalidate_tlbs request has been seen to marginally exceed the
configured 100 ms timeout on systems under load.

All other KIQ requests in the driver use a 10 second timeout. Use a
similar timeout implementation on the invalidate_tlbs path.

v2: Poll once before msleep
v3: Fix return value

Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Cc: Kent Russell <kent.russell@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>