Bluetooth: Tidy-up coding style in hci_bcsp.c

drivers/bluetooth/hci_bcsp.c contains some style issues as
highlighted by

./scripts/checkpatch.pl --strict -f drivers/bluetooth/hci_bcsp.c

a) comments - maintainer prefers network style comments
b) positioning of lines in multi-line statements
c) spaces after casts
d) missing blank lines after declarations

Therefore, tidy-up the above to make it easier to apply
future code changes that have conforming style.

Signed-off-by: Dean Jenkins <Dean_Jenkins@mentor.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>