test_libaom: add a check for sse4.2
test_libaom: add a check for sse4.2

sse4.2 functions were added in:
ffda3774f Add SSE4_2 version of crc hash function

BUG=aomedia:1504

Change-Id: I7fd81c43a253cd2d13789288d9de363aa270557b

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