openpic: Move definition of openpic_reset

This patch moves the definition of openpic_reset after the various
register read/write functions. No functional change.  It is in
preparation for using the register read/write functions in
openpic_reset.

Signed-off-by: Paul Janzen <pcj@pauljanzen.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
openpic: Reset IRQ source private members

The openpic emulation code maintains an allowable-CPU's bitmap
("destmask") for each IRQ source which is calculated from the IDR
register value whenever the guest OS writes to it.  However, if the
guest OS relies on the system to set the IDR register to a default
value at reset, and does not write IDR, then destmask does not get
updated, and interrupts do not get propagated to the guest.
Additionally, if an IRQ source is marked as critical, the source's
internal "output" and "nomask" fields are not correctly reset when the
PIC is reset.

Fix both these issues by calling write_IRQreg_idr from within
openpic_reset, instead of simply setting the IDR register to the
specified idr_reset value.

Signed-off-by: Paul Janzen <pcj@pauljanzen.org>
Signed-off-by: Alexander Graf <agraf@suse.de>
PPC: openpic_kvm: Implement reset

When we trigger a system reset, the in-kernel openpic controller should also
get reset. This happens through a write to the GCR.RESET register which is
the same mechanism a guest would use to manually reset the device.

Signed-off-by: Alexander Graf <agraf@suse.de>