dt-bindings: net: bluetooth: qca: Expand firmware-name property

Expand the firmware-name property to specify the names of NVM and
rampatch firmware to load. This update will support loading specific
firmware (nvm and rampatch) for certain chips, like the QCA6698
Bluetooth chip, which shares the same IP core as the WCN6855 but has
different RF components and RAM sizes, requiring new firmware files.

We might use different connectivity boards on the same platform. For
example, QCA6698-based boards can support either a two-antenna or
three-antenna solution, both of which work on the sa8775p-ride platform.
Due to differences in connectivity boards and variations in RF
performance from different foundries, different NVM configurations are
used based on the board ID.

So In firmware-name, if the NVM file has an extension, the NVM file will
be used. Otherwise, the system will first try the .bNN (board ID) file,
and if that fails, it will fall back to the .bin file.

Possible configurations:
firmware-name = "QCA6698/hpnv21.bin", "QCA6698/hpbtfw21.tlv";
firmware-name = "QCA6698/hpnv21", "QCA6698/hpbtfw21.tlv";
firmware-name = "QCA6698/hpnv21.bin";

Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Cheng Jiang <quic_chejiang@quicinc.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>