Bluetooth: btintel: Fix the sfi name for BlazarU

Use INTEL_HW_VARIANT() instead of CNVi Id to decide to load Intermediate
Loader (IML) image. Fix the driver loading incorrect firmware for
BlazarU product.

dmesg:
.....
[146.111834] Bluetooth: hci0: Minimum firmware build 1 week 10 2014
[146.111839] Bluetooth: hci0: Bootloader timestamp 2022.18 buildtype 1 build 16362
[146.111848] Bluetooth: hci0: No support for _PRR ACPI method
[146.112204] Bluetooth: hci0: Failed to load Intel firmware file intel/ibt-0291-0291-iml.sfi (-2)

Fixes: 164c62f9

 ("Bluetooth: btintel: Add firmware ID to firmware name")
Reported-by: Tsigan, Vladislav <vladislav.tsigan@intel.com>
Signed-off-by: Kiran K <kiran.k@intel.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>