iidtx4_sse2: silence tran_high conv warning
iidtx4_sse2: silence tran_high conv warning

cast Sqrt to short, _mm_set1_epi16 expects this as input

Change-Id: I667cd0bfcc86acfa5ccd7069f02e4dd1ec7b6bae

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