anv/pipeline: Don't dereference NULL dynamic state pointers

anv/pipeline: Don't dereference NULL dynamic state pointers

Add guards to prevent dereferencing NULL dynamic pipeline state. Asserts
of pCreateInfo members are moved to the earliest points at which they
should not be NULL.

This fixes a segfault seen in the McNopper demo, VKTS_Example09.

v3 (Jason Ekstrand):
   - Fix disabled rasterization check
   - Revert opaque detection of color attachment usage

Signed-off-by: Nanley Chery <nanley.g.chery@intel.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Cc: "12.0" <mesa-stable@lists.freedesktop.org>