gralloc: Allocate cached by default, don't use bitops on SW flags

Allocate gralloc buffers cached by default unless clients specify
uncached using PRIVATE_UNCACHED or READ_RARELY or WRITE_RARELY at
allocation time. Some clients could use gralloc for allocation but
later won't use lock()/unlock() for CPU operations and likely use
their own caching methods. Cached by default helps such clients.

SW usage flags are not defined as bit values, so do not use bitops
on those flags.

Change-Id: Id371de2ec6efbfa0ed84172b3540f3ebc8f5d459
6 files changed