Bluetooth: btqca: Introduce generic QCA ROME support

This is for supporting BT for QCA ROME with vendor specific
HCI commands and initialization on the chip. This will have
USB/UART implementation both, but for now, adding UART vendor
specific commands to patch downloading and set Bluetooth device
address using vendor specific command.

Signed-off-by: Ben Young Tae Kim <ytkim@qca.qualcomm.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>