avrcp: return NOT_IMPLEMENTED on request for vendor dep command
avrcp: return NOT_IMPLEMENTED on request for vendor dep command

When a vendor dependent command is requested but target does not
implement it, the correct return value is CTYPE_NOT_IMPLEMENTED instead
of CTYPE_REJECTED.

AVRCP 1.3 spec clearly says so on section 4.5.1:
	[ It is assumed that devices that do not support this metadata
	transfer related features shall return a response of NOT
	IMPLEMENTED as per AV/C protocol specification ]

And AV/C General Specification, section 8.3.2 talks about legacy
behavior and mandates that NOT_IMPLEMENTED is returned.

Finally, in section 11.6.1 we see that VENDOR-DEPENDENT command frame
depends on the company_ID. Therefore we can't assume it has the same
format as the one specified for metadata transfer (in case the company
ID is 0x001958)

pkarasev3/bluez,mapfau/bluez,pstglia/external-bluetooth-bluez,mapfau/bluez,mapfau/bluez,ComputeCycles/bluez,mapfau/bluez,silent-snowman/bluez,pkarasev3/bluez,silent-snowman/bluez,pkarasev3/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,pkarasev3/bluez,ComputeCycles/bluez,pstglia/external-bluetooth-bluez,pstglia/external-bluetooth-bluez,ComputeCycles/bluez,silent-snowman/bluez,silent-snowman/bluez