Use aom_reader with od_decode_pvq_codeword().

Change the od_decode_pvq_codeword() function to take an aom_reader
 struct instead of an od_ec_dec struct.
Rename od_decode_pvq_codeword() to aom_decode_pvq_codeword().

Change-Id: I9fc2dda28a6169cb04410e822070991f3bcbc25a
1 file changed