i965, anv: Use INTEL_DEBUG for disk_cache driver flags

i965, anv: Use INTEL_DEBUG for disk_cache driver flags

Since various options within INTEL_DEBUG could impact code generation,
we need to set the disk cache driver_flags parameter based on the
INTEL_DEBUG flags in use.

An example that will affect the program generated by i965 is the
INTEL_DEBUG=nocompact option.

The DEBUG_DISK_CACHE_MASK value is added to mask the settings of
INTEL_DEBUG that can affect program generation.

v2:
 * Use driver_flags (Tim)
 * Also update Anvil (Jason)

Signed-off-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>