Bluetooth: hciuart: Fix to use boolean flag with u32 type

debugfs_create_bool is asking to put u32 type pointer instead of bool
so that passing bool type with u32* cast will cause memory corruption
to read that value since it is handled by 4 bytes instead of 1 byte
inside.

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