powerpc: don't disable SATA interrupts on Freescale MPC8610 HPCD

The ULI 1575 PCI quirk function for the Freescale MPC8610 HPCD was disabling
the SATA INTx interrupt, even when SATA support was enabled.  This was safe,
because the SATA driver re-enabled it.  But with commit a5bfc471

 ("ahci: drop
intx manipulation on msi enable"), the driver no longer does this, and so SATA
support on the 8610 HPCD is broken.

The original quirk function disabled INTx because it caused some other
interrupt problem during early development on this board, but no one remembers
any more what that problem was, and it doesn't seem to occur any more.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>