i965: Port gen4+ emit vertices code to genxml.

i965: Port gen4+ emit vertices code to genxml.

Some code that was placed in brw_draw_upload.c and exported to be used
by gen8+ was also moved to genX_state_upload, and the respective symbols
are not exported anymore.

v2:
   - Remove code from brw_draw_upload too
   - Emit vertices for gen4-5 too.
   - Use helper to setup brw_address (Kristian)
   - Use macros for MOCS values.
   - Do not use #ifndef NDEBUG on code that is actually used (Ken)
v3:
   - Style and code clenup (Ken)
   - Keep some of the common code inside brw_draw_upload.c (Ken)

Signed-off-by: Rafael Antognolli <rafael.antognolli@intel.com>
Reviewed-by: Kenneth Graunke <kenneth@whitecape.org>