frontends/va: Fix test_va_api VAAPIDisplayAttribs tests
Set max_display_attribs to 0 instead of 1 to match va[Query,Get,Set]DisplayAttributes implementations [1].
If max_display_attribs is greater than 0 libva-utils tests check vaQueryDisplayAttributes() accordingly [2].
[2] https://github.com/intel/libva-utils/blob/master/test/test_va_api_display_attribs.cpp#L90
Signed-off-by: Ed Baker edward.baker@intel.com