i965: Replace BRW_SURFACEFORMAT_* with ISL_FORMAT_*.

i965: Replace BRW_SURFACEFORMAT_* with ISL_FORMAT_*.

One less set of enums.  Dropped the #defines from brw_defines.h and ran:

$ for file in *.cpp *.c *.h; do sed -i \
      -e 's/BRW_SURFACEFORMAT_/ISL_FORMAT_/g' \
      -e 's/ISL_FORMAT_ASTC_[A-Zxs0-9_]*/\U&/g' $file; \
  done

Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>