Do not refer to enhancement_layers_cnt in comment.
Do not refer to enhancement_layers_cnt in comment.

aom_codec_stream_info_t::enhancement_layers_cnt was removed in
https://aomedia-review.googlesource.com/c/aom/+/57961. Update the
comment for AV1D_SET_OPERATING_POINT to not refer to
aom_codec_stream_info_t::enhancement_layers_cnt.

Change-Id: Iae6907393247f52e94d2e7e70716f11e294c062e

GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom,GrokImageCompression/aom