amdfam10 boards: Drop const variables sbdn_sb800 and sbdn_sb700

They evaluate to const zero and obscure PCI_DEVFN() use.

Change-Id: I8bd8dced62094d5ee8e957241ac29ead054f5c05
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/30632
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/mainboard/advansus/a785e-i/mptable.c

@@ -22,7 +22,6 @@
 
 extern u8 bus_sb800[6];
 extern u32 apicid_sb800;
-extern u32 sbdn_sb800;
 
 u8 intr_data[] = {
 	[0x00] = 0x10,0x11,0x12,0x13,0x14,0x15,0x16,0x17, /* INTA# - INTH# */