m68k: don't export static inline functions

These now cause errors due to changes present in linux-next:

(__ksymtab_sorted+0x1258): undefined reference to `dio_dev_driver'
(__ksymtab_sorted+0x4d48): undefined reference to `zorro_dev_driver'

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>