aom: fix compilation with older packages
AOM_USAGE_ALL_INTRA isn't being defined while AOM_USAGE_GOOD_QUALITY is, refs https://aomedia.googlesource.com/aom/+/refs/tags/v3.0.0/aom/aom_encoder.h#1001
AOM_USAGE_ALL_INTRA isn't being defined while AOM_USAGE_GOOD_QUALITY is, refs https://aomedia.googlesource.com/aom/+/refs/tags/v3.0.0/aom/aom_encoder.h#1001
VideoLAN code repository instance