ppc/pnv: Improve trigger data definition

The trigger data is used for both triggers of a HW source interrupts,
PHB, PSI, and triggers for rerouting interrupts between interrupt
controllers.

When an interrupt is rerouted, the trigger data follows an "END
trigger" format. In that case, the remote IC needs EAS containing an
END index to perform a lookup of an END.

An END trigger, bit0 of word0 set to '1', is defined as :

             |0123|4567|0123|4567|0123|4567|0123|4567|
    W0 E=1   |1P--|BLOC|          END IDX            |
    W1 E=1   |M   |           END DATA               |

An EAS is defined as :

             |0123|4567|0123|4567|0123|4567|0123|4567|
    W0       |V---|BLOC|          END IDX            |
    W1       |M   |          END DATA                |

The END trigger adds an extra 'PQ' bit, bit1 of word0 set to '1',
signaling that the PQ bits have been checked. That bit is unused in
the initial EAS definition.

When a HW device performs the trigger, the trigger data follows an
"EAS trigger" format because the trigger data in that case contains an
EAS index which the IC needs to look for.

An EAS trigger, bit0 of word0 set to '0', is defined as :

             |0123|4567|0123|4567|0123|4567|0123|4567|
    W0 E=0   |0P--|---- ---- ---- ---- ---- ---- ----|
    W1 E=0   |BLOC|            EAS INDEX             |

There is also a 'PQ' bit, bit1 of word0 to '1', signaling that the
PQ bits have been checked.

Introduce these new trigger bits and rename the XIVE_SRCNO macros in
XIVE_EAS to reflect better the nature of the data.

Signed-off-by: Cédric Le Goater <clg@kaod.org>
Message-Id: <20191007084102.29776-2-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>