av1_rtcd_defs.pl: remove dead declarations
av1_rtcd_defs.pl: remove dead declarations

Change-Id: I4adc76fc36e8810854862136eddc39f65037c2b3

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