Add another if case for convolve_2d_copy_sse2
Add another if case for convolve_2d_copy_sse2

Load four 8-bit input and process.

Change-Id: I9b3ba58ea3a03c6a8129379afa37c54a57e04501

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