[POWERPC] 4xx: Set ibpre for 405EX in 4xx PCIe driver

This patch sets the ibpre flag (Inbound Presence) for the 405EX
in the 4xx PCIe driver.
Signed-off-by: NStefan Roese <sr@denx.de>
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>

arch/powerpc/sysdev/ppc4xx_pci.c

@@ -844,6 +844,8 @@ static int ppc405ex_pciex_init_port_hw(struct ppc4xx_pciex_port *port)
 
 	dcr_write(port->dcrs, DCRO_PEGPL_CFG, 0x10000000);  /* guarded on */
 
+	port->has_ibpre = 1;
+
 	return 0;
 }