i965: Create a hardware context before initializing state module.

brw_init_state() calls brw_upload_initial_gpu_state().  If hardware
contexts are enabled (brw->hw_ctx != NULL), this will upload some
initial invariant state for the GPU.  Without hardware contexts, we
rely on this state being uploaded via atoms that subscribe to the
BRW_NEW_CONTEXT bit.

Commit 46d3c2bf4ddd227193b98861f1e632498fe547d8 accidentally moved
the call to brw_init_state() before creating a hardware context.
This meant brw_upload_initial_gpu_state would always early return.
Except on Gen6+, we stopped uploading the initial GPU state via
state atoms, so it never happened.

Fixes a regression since 46d3c2bf4ddd227193b98861f1e632498fe547d8.

Cc: "10.0 10.1" <mesa-stable@lists.freedesktop.org>
Signed-off-by: Kenneth Graunke <kenneth@whitecape.org>
Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
(cherry picked from commit 3663bbe773187dee341556ef29e58b1143ef2f5c)