Update headers after adding RS_TYPE_FLOAT_16 and helpers

http://b/24862914

Update RS headers after adding
- RS_TYPE_FLOAT_16 value to rs_data_type enum
- helper functions to create float16 allocations

Change-Id: Id674db3902aff3fe41b0c0b5c336dab60b6e66ce
(cherry picked from commit 5f3e70c4662079b434a4808380f28dd030ebb6f4)
2 files changed