Bluetooth: btintel: Allow configuring drive strength of BRI

BRI (Bluetooth Radio Interface) traffic from CNVr to CNVi was found causing
cross talk step errors to WiFi. To avoid this potential issue OEM platforms
can replace BRI resistor to adjust the BRI response line drive strength.
During the *setup*, driver reads the drive strength value from uefi
variable and passes it to the controller via vendor specific command with
opcode 0xfc0a.

dmesg:

..
[21.982720] Bluetooth: hci0: Bootloader timestamp 2023.33 buildtype 1 build 45995
[21.984250] Bluetooth: hci0: Found device firmware: intel/ibt-0190-0291-iml.sfi
[21.984255] Bluetooth: hci0: Boot Address: 0x30099000
[21.984256] Bluetooth: hci0: Firmware Version: 160-24.24
[22.011501] Bluetooth: hci0: Waiting for firmware download to complete
[22.011518] Bluetooth: hci0: Firmware loaded in 26624 usecs
[22.011584] Bluetooth: hci0: Waiting for device to boot
[22.013546] Bluetooth: hci0: Malformed MSFT vendor event: 0x02
[22.013552] Bluetooth: hci0: Device booted in 1967 usecs
...
[22.013792] Bluetooth: hci0: dsbr: enable: 0x01 value: 0x0b
...
[22.015027] Bluetooth: hci0: Found device firmware: intel/ibt-0190-0291.sfi
[22.015041] Bluetooth: hci0: Boot Address: 0x10000800
[22.015043] Bluetooth: hci0: Firmware Version: 160-24.24
[22.395821] Bluetooth: BNEP (Ethernet Emulation) ver 1.3
[22.395828] Bluetooth: BNEP filters: protocol multicast
...

Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>