This just fixes up the enables for native integers and EXT_texture_integer
support in st/mesa.

It also set the MaxClipPlanes to 8.

We should consider exposing caps for MCP vs MCD, but since core
mesa doesn't care yet maybe we can wait for now.

v2: use 32-bit formats as per Marek's mail.

v3: add calim's fix for INT_DIV_TO_MUL_RCP disabling.

Signed-off-by: Dave Airlie <airlied@redhat.com>