Bluetooth: Add __init/__exit macros to Marvell SDIO driver

Trivial patch which adds the __init/__exit macros to the module_init/
module_exit functions of btmrvl_sdio.c driver.

Signed-off-by: Peter Huewe <peterhuewe@gmx.de>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>