tweak vp8_regular_quantize_b_sse2

rather than look up rc in the zig zag table, embed it in the macro. this
also allows us to shuffle some values in the macro and keep *d in rsi

gains of about the same order as the obj_int_extract implementation: ~2%

Change-Id: Ib7252dd10eee66e0af8b0e567426122781dc053d