Currently the bcm_uart_subver_ and bcm_usb_subver_table-s lack entries
for the BCM4324B5 and BCM20703A1 chipsets. This makes the code use just
"BCM" as prefix for the filename to pass to request-firmware, making it
harder for users to figure out which firmware they need. This especially
is problematic with the UART attached BCM4324B5 where this leads to the
filename being just "BCM.hcd".

Add the 2 missing devices to subver tables. This has been tested on:

1. A Dell XPS15 9550 where this makes btbcm.c try to load
"BCM20703A1-0a5c-6410.hcd" before it tries to load "BCM-0a5c-6410.hcd".

2. A Thinkpad 8 where this makes btbcm.c try to load
"BCM4324B5.hcd" before it tries to load "BCM.hcd"
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>