ppc/pnv: Generate phandle for the "interrupt-parent" property

ppc/pnv: Generate phandle for the "interrupt-parent" property

Devices such as the BT or serial devices require a valid
"interrupt-parent" phandle in the device tree and it is currently
empty (0x0). It was not a problem until now but since OpenFirmare
started using a recent libdft (>= 1.4.7), petitboot fails to boot the
system image with error :

   dtc_resize: fdt_open_into returned FDT_ERR_BADMAGIC

Provide a phandle for the LPC bus.

Suggested-by: Greg Kurz <[email protected]>
Signed-off-by: Cédric Le Goater <[email protected]>
Message-Id: <20190723090138[email protected]>
Signed-off-by: David Gibson <[email protected]>