i965: emit BRW_NEW_AUX_STATE on aux state changes

i965: emit BRW_NEW_AUX_STATE on aux state changes

Fixes a regression introduced with b96313c0e1289b296d7, which removed
BRW_NEW_BLORP for a bunch of SURFACE_STATE setup code, including render
targets, on the basis that blorp invalidates binding tables but not
surface states, however, at least on Broadwell, this caused a regression
in a CTS test, which Ken and Jason tracked down to the fact that we
are not uploading new render target surface states after allocating
new CCS_D surfaces for fast clears (which allocation is deferred until
an actual clear occurs).

The reason this only fails in BDW is that on SKL+ we use CCS_E which
is allocated up front so it exists in the initial surface state, the
problem can be reproduced in these platforms too if we use
INTEL_DEBUG=norcb to force the CCS_D path.

This patch, together with the ones preceding it, fixes the regression
by ensuring that we track and flag as dirty all aux state changes.

Credit goes to Jason and Ken for figuring out the reason for the
regression.

Fixes:
KHR-GL45.transform_feedback.draw_xfb_test

Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>