AGESA: Call get_bus_conf() just once

Instead of calling get_bus_conf() three times from write_tables()
and executing it once, just make one call before entering write_tables().

Change-Id: I818e37128cb0fb5eaded3c1e00b6b146c1267647
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/6133
Tested-by: build bot (Jenkins)
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>

src/mainboard/amd/parmer/irq_tables.c

@@ -57,8 +57,6 @@ unsigned long write_pirq_routing_table(unsigned long addr)
 	u8 sum = 0;
 	int i;
 
-	get_bus_conf();		/* it will find out all bus num and apic that share with mptable.c and mptable.c and acpi_tables.c */
-
 	/* Align the table to be 16 byte aligned. */
 	addr += 15;
 	addr &= ~15;