greybus: audio: apbridgea: Remove GET_TX/RX_DELAY message types

The 'AUDIO_APBRIDGEA_TYPE_GET_TX_DELAY' and
'AUDIO_APBRIDGEA_TYPE_GET_RX_DELAY' message types have been
removed from the AP <-> APBrigdeA Audio Protocol so remove
them from the code.  Do not coalesce the message type numbers
to prevent compatibility issues between the AP and APBridgeA.

Testing Done: Played music using a speaker module

Signed-off-by: Mark Greer <mgreer@animalcreek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>