anv: track render targets & render area changes separately

anv: track render targets & render area changes separately

The following instructions :
   - 3DSTATE_VIEWPORT_STATE_POINTERS_SF_CLIP
   - 3DSTATE_VIEWPORT_STATE_POINTERS_CC
   - 3DSTATE_SCISSOR_STATE_POINTERS

do not care about the content/format/count of the render targets, only
the size of the render area and count of viewport/scissor.

By tracking render targets & render area we can reduce the emission of
those instructions.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/25778>