[SCSI] qla4xxx: fix build on PPC

We use read/write[bslq] but do not include linux/io.h. This causes
build failures on PPC. Include that file.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Cc: Stable Tree <stable@kernel.org>
Acked-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>