Add inter related cost in handle_inter_mode
Add inter related cost in handle_inter_mode

This is to facilitate doing inter mode rd prediction

Coding performance changed within 0.01% range

Change-Id: I2f390fcba6e31cd855f5dd63ef439827e1862e8b

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