We have Vulkan utilities in both src/util and src/vulkan/util. The
latter seems a more appropriate place for Vulkan-specific things, so
move them there.

v2: Android build system changes (from Tapani Pälli)
Signed-off-by: Alex Smith <asmith@feralinteractive.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Reviewed-by: Eric Engestrom <eric.engestrom@imgtec.com>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>