Bluetooth: bluecard_cs: Shorten scope for iobase

Shortening scope shall silence some warnings reported by Geert
Uytterhoeven:

...
drivers/bluetooth/bluecard_cs.c: warning: unused variable 'iobase'
	[-Wunused-variable]
...

Signed-off-by: Andrei Emeltchenko <andrei.emeltchenko@intel.com>
Signed-off-by: Gustavo Padovan <gustavo.padovan@collabora.co.uk>