Bluetooth: btnxpuart: Drop _v0 suffix from FW names

This updates all FW names by dropping the _v0 suffix.
Its been decided that all NXP BT/ WiFi FW names won't support _v0 suffix.
The suffix would be kept for next HW versions such as v1, v2 and so on,
which do not have backward compatible FW.

This change affects W8987, IW416 and IW615 chipsets, out of which new FW
files for W8987 and IW615 are yet to be released to broad market.

For IW416, old and new FW names are added to maintain backward
compatibility for existing customers.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>