section fixes for cirrusfb

cirrusfb_zorro_unmap() may be called both from __devexit and (on
cleanup path) from __devinit.  So it needs to be a normal function,
same as for cirrusfb_pci_unmap()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>