Bluetooth: Devcoredump: Fix storing u32 without specifying byte order issue

API hci_devcd_init() stores its u32 type parameter @dump_size into
skb, but it does not specify which byte order is used to store the
integer, let us take little endian to store and parse the integer.

Fixes: f5cc609d09d4 ("Bluetooth: Add support for hci devcoredump")
Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>