powerpc/powernv: Replace OPAL_DEASSERT_RESET with EEH_RESET_DEACTIVATE

The flag passed to ioda_eeh_phb_reset() should be EEH_RESET_DEACTIVATE,
which is translated to OPAL_DEASSERT_RESET or something else by the
EEH backend accordingly.

The patch replaces OPAL_DEASSERT_RESET with EEH_RESET_DEACTIVATE for
ioda_eeh_phb_reset().

Cc: stable@vger.kernel.org
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>