[SPARC64]: fix sparc_floppy_irq's auxio_register reseting

[SPARC64]: fix sparc_floppy_irq's auxio_register reseting

The patch "[SPARC64]: Get rid of fast IRQ feature"
moved the the code from arch/sparc64/kernel/entry.S:
      lduba           [%g7] ASI_PHYS_BYPASS_EC_E, %g5
      or              %g5, AUXIO_AUX1_FTCNT, %g5
      stba            %g5, [%g7] ASI_PHYS_BYPASS_EC_E
      andn            %g5, AUXIO_AUX1_FTCNT, %g5
      stba            %g5, [%g7] ASI_PHYS_BYPASS_EC_E
to arch/sparc64/kernel/irq.c:
              val = readb(auxio_register);
              val |= AUXIO_AUX1_FTCNT;
              writeb(val, auxio_register);
              val &= AUXIO_AUX1_FTCNT;
              writeb(val, auxio_register);
This looks like it it missing a bitwise not, which is reintroduced
by this patch.

Due to lack of a floppy device, I could not test it, but it looks
evident.

Signed-off-by: Bernhard R Link <brlink@debian.org>
Signed-off-by: David S. Miller <davem@davemloft.net>