isdn: fix section mismatch warning for ISACVer

Fix following warnings:
WARNING: drivers/isdn/hisax/built-in.o(.text+0x19723): Section mismatch in reference from the function ISACVersion() to the variable .devinit.data:ISACVer
WARNING: drivers/isdn/hisax/built-in.o(.text+0x2005b): Section mismatch in reference from the function setup_avm_a1_pcmcia() to the function .devinit.text:setup_isac()

ISACVer were only used from function annotated __devinit
so add same annotation to ISACVer.
One af the fererencing functions missed __devinit so add it
and kill an additional warning.

Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Karsten Keil <kkeil@suse.de>
Cc: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>